Ellery Queen’s Anthology. Volume 1, 1960

John Dickson Carr Strictly Diplomatic

Even to the secret service story John Dickson Carr affixes his famous hallmark — the impossible crime that in the end proves to be wholly possible. In this case, how did the former schoolmistress “vanish life a puff of smoke”? And this time Mr. Carr adds something new: one of the most unhackneyed motives in the modern detective short story...

Now that he was nearly at the end of his rest-cure, Dermot had never felt so well in his life.

He leaned back in the wicker chair, flexing his muscles. He breathed deeply. Below him the flattish lands between France and Belgium sloped to the river: a slow Flemish river dark green with the reflection of its banks. Half a mile away he could see the houses of the town, with the great glass roof of the spa smoky in autumn sunshine. Behind him — at the end of the arbor — was the back of the hotel, now denuded of its awnings.

They had taken down the awnings; they were closing up many of the bedrooms. Only a few guests now pottered about the terrace. A crisp tang had come into the air: work, and the thunder of London again, now loomed up as a pleasant prospect. Once, hardly a month ago, it had been a nightmare of buses charging straight at you, like houses loose; a place where nerves snapped, and you started to run.

Even with that noise in his ears, he had not wanted to go away.

“But I can’t take a holiday now!” he had told the doctor.

“Holiday?” snorted the doctor. “Do you call it a holiday? Your trouble is plain overwork, a complaint we don’t often get nowadays. Why don’t you relax? Not hard up, are you?”

“No, it isn’t that.”

“You’re too conscientious,” the doctor had said, rather enviously.

“No. It’s not a virtue,” said Dermot, as honestly as he could. “I can’t help it. Every second I’m away from work, I’m worrying about it until I get back. I’m built like that. I can’t relax. I can’t even get drunk.”

The doctor grunted.

“Ever try falling in love?”

“Not since I was nineteen. And, anyway, it’s not something you can take down like a box of pills and dose yourself with. Or at least I can’t.”

“Well,” said the doctor, surveying him. “I know a rising barrister who’s going to come a cropper unless you get out of this. Now I warn you. You get off to the Continent this week. There’s a spa I know — Ile St. Cathérine. The waters won’t do you any harm; and the golf will do you good.”

Here the doctor, who was an old friend of Andrew Dermot’s, grinned raffishly.

“What you want,” he added, “is adventure. In the grand manner. I hear there’s a fenced-off area near Ile St. Cathérine, bayonets and all. The casino is probably full of beautiful slant-eyed spies with jade ear-rings. Forget you’re turning into such a moss-back. Pick up one of the beautiful slant-eyed spies, and go on the razzle-dazzle with her. It’ll do you all the good in the world.”

Alone on the lawn behind his hotel, Dermot laughed aloud. Old Foggy had been right, in a way. But he had gone one less or one better than that. He had fallen in love.

Anyone less like a slant-eyed spy than Betty Weatherill would be difficult to imagine. In face even the tension which tautened nerves in the rest of Europe did not exist in lie St. Catherine. It was a fat, friendly, rather stodgy sort of place. Looking round the spa — where fountains fell, and people got very excited on the weighing-machines — Dermot wondered at old Foggy’s notion of bayonets. He felt soothed, and free. Bicycle-bells tingled in the streets under once-gilded houses. At night, when you ordered thin wine by the glass, a band played beneath lights in the trees. A mild flutter in roulette at the casino caused excitement; and one Belgian burgher was caught bringing his supper in a paper packet.

Dermot first saw Betty Weatherill on the morning after his arrival.

It was at breakfast. There were not many guests at the hotel: a fat Dutchman eating cheese for breakfast, half a dozen English people, a foreign envoy, a subdued French couple. And, of course, the sturdy girl who sat alone at the sun-steeped table by the windows.

Dermot’s nerves were still raw from the journey. When he first saw her he felt a twinge of what he thought was envy at her sheer health. It flashed out at him. He had an impression of a friendly mouth, a sun-tanned complexion; of eagerness, and even naÏvete. It disturbed him like the clattering coffee-cups. He kept looking round at her, and looking round again, though he did not understand why.

He played execrable golf that day.

He saw her again next morning. They ran into each other buying stamps at the cash-desk. They both smiled slightly, and Dermot felt embarrassed. He had been trying to remember whether the color of her hair was fair or chestnut; it was, he saw, a light brown. That afternoon his golf was even worse. It was absurd that he, thirty-five years old, should seem as stale and crumpled as an old poster against a wall. He was a nerve-ridden fool. He fell to thinking of her again.

On the following day they went so far as to say good morning. On the third day he took his nerve in both hands, and plumped down at the breakfast-table next to hers.

“I cant do it,” he heard her say, half-laughing.

The words gave him a start. Not a ladies’ man, this move of his had struck him as distinctly daring. Yet he felt the communication between them, an uncomfortable awareness of each other’s presence. He looked up, to find her eyes fixed on him.

“Do what?” he asked quickly.

“Manage Continental breakfasts,” she answered, as though they were old friends discussing a problem of mutual importance. “I know I shouldn’t, but every day I order bacon and eggs.”

After that their acquaintance was off at a gallop.

Her name was Betty Weatherill. She was twenty-eight, and came from Brighton. She had been a schoolmistress (incongruous idea); but she had come into a small inheritance and, as she confessed, was blueing part of it. He had never met a girl who seemed so absolutely right: in what she said, in what she did, in her response to any given remark.

That afternoon they went to the fair and ate hot dogs and rode round and round on the wooden horses to the panting music of an electric piano. That night they dressed for the casino; and Andrew Dermot, shuffling roulette-counters, felt no end of an experienced gay-dog. And the knowledge came to him, with a kind of shock, “Good lord, I’m alive.”

Betty was popular at the hotel. The proprietor, Monsieur Gant, knew her quite well and was fond of her. Even the fat Dr. Vanderver, of the Sylvanian Embassy, gave her a hoarse chuckle of appreciation whenever she went by. Not that she had no difficulties. There was, it appeared, some trouble about her passport. She had several times to go to the prefecture of police — from which she emerged flushed, and as near angry as it was possible for her to be.

As for Dermot, he was in love and he knew it. That was why he exulted when he sat by the teatable on the lawn behind the hotel, at half-past five on that lazy, veiled autumn afternoon, waiting for Betty to join him. The lawn was dotted with little tables, but he was alone. The remains of tea and sandwiches were piled on a tray. Dermot was replete; no outside alarms troubled Ile St. Cathérine; no black emblems threw shadows.

This was just before he received the greatest shock of his life.

“Hello!” said Betty. “Sorry I’m late.” She came hurrying out of the arbor, with the breathless smile she always wore when she was excited. She glanced quickly round the lawn, deserted except for a waitress slapping at crumbs. Dermot got up.

“You’re not late,” he told her. “But you swore to me you were going to have tea in town, so I went ahead.” He looked at her suspiciously. “Did you?”

“Did I what?”

“Have tea.”

“Yes, of course.”

For no reason that he could analyze, a chill of uneasiness came to Dermot. His nightmares were cured. But it was as though an edge of the nightmare returned. Why? Only because the atmosphere suddenly seemed wrong, because the expression of her eyes was wrong. He drew out a chair for her.

“Sure you wouldn’t like another cup? Or a sandwich?”

“Well—”

Now he thought he must be a fool reading huge meanings into trifles. But the impression persisted. He gave an order to the waitress, who removed the tea-tray and disappeared into the arbor. Betty had taken a cigarette out of her handbag; but, when he tried to light it for her, the cigarette slipped out of her fingers, rolled on the table.

“Oh, damn,” she whispered. Now he was looking into her eyes from a short distance away; they seemed the eyes of a slightly older, wiser woman. They were hazel eyes, the whites very clear against a sun-tanned face. The heavy lids blinked.

“I want to know what’s wrong,” Dermot said.

“There’s nothing wrong,” said Betty, shaking her head. “Only — I wanted to talk to you. I’m afraid I’ve got to leave here.”

“When?”

“Tonight.”

Dermot sat up. It seemed to him that there was a stranger sitting across from him, and that all his plans were toppling.

“If you must, you must,” he said. “But I’ve got to go myself at the beginning of the week. I thought we were going to leave together.”

“I can’t. Very shortly” — she spoke with some intensity — “I hope I can explain to you what a beast I am. All I can tell you now is that it’s not altogether safe for me to be here.”

“Safe? In this place?”

Betty was not listening. She was wearing white, as he always remembered afterwards, with a white handbag. Again she had opened this handbag, and was going through it in something of a hurry.

“Derry.” She spoke sharply. “You haven’t seen my compact, have you? The white ivory one with the red band?” She looked round; “It didn’t fall out when I opened my handbag before?”

“No, I don’t think so. I didn’t see it.”

“I must have left it back in my room. Please excuse me. I’ll be back in half a tick.”

And she got to her feet, snapped shut the catch of the handbag.

Dermot also got up. It would not be fair to say that he exploded. He was a mild-mannered man who arrived at all emotions with difficulty. But in the past few minutes he felt that a door had opened on a world he could not understand.

“Look here, Betty,” he said. “I don’t know what’s got into you; but I insist on knowing. If there’s anything wrong, just tell me and we’ll put it right. If—”

“I’ll be back in a moment,” she assured him.

And, disregarding the hand he put out, she hurried back through the arbor.

Dermot sat down heavily, and stared after her. A veiled sun had turned the sky to grey, making dingy the cloths of the little tables on the lawn. The cloths fluttered under a faint breeze.

He contemplated the arbor, which was a very special sort of arbor. Monsieur Gant, the proprietor of the Hotel Suchard, had imported it from Italy and was very proud of it. Stretching back s full twenty yards to the rear terrace of the hotel, it made a sort of tunnel composed of tough interlaced vines which in summer were heavy with purplish-pink blossom. A line of tables ran beside it, with lights from above. Inside the arbor, at night, Chinese lanterns hung from the roof. It was one of the romantic features of the hotel. But at the moment — cramped, unlighted, hooded with thick foliage — it was a tunnel which suggested unpleasant images.

“A good place for a murder,” Betty had once laughed.

Andrew Dermot could hear his watch ticking. He wished she would come back.

He lit a cigarette and smoked it to a stump; but she had not returned. He got to his feet, stamping on the chilling grass. For the first time he glanced across the tea-table at Betty’s empty chair. It was a wicker chair. And, lying on the seat in plain view, was a white ivory compact with a red band.

So that was it! She had been too much upset to notice the compact, of course. She was probably still searching her room for it.

He picked up the compact and went after her.

Inside the arbor it was almost dark, but chinks and glimmers of light flickered through interlaced vines and showed him an arched tunnel some ten feet high, with a floor of packed sand. There was a stagnant smell of dying blossom; the Judas tree, did they call it? Obscurely, he was relieved to find the gnat-stung arbor empty. He hurried along its length to the arch of light at the end, and emerged on a red-tiled terrace where there were more tables under the windows.

“Good eefening, Mr. Dermot,” said an affable voice.

Dermot checked his rush.

He almost stumbled over Dr. Henrik Vanderver of the Sylvanian Embassy, who was sitting near the arbor, smoking a cigar with relish, and looking at him through thick-lensed spectacles.

“Ha, ha, ha!” said Dr. Vanderver, laughing uproariously and for no apparent reason; as was his custom.

“Good evening, Dr. Vanderver,” said Dermot. His uneasiness had gone; he felt again a nerve-ridden fool. “Sorry to barge into you like that. Is Miss Weatherill down yet?”

Dr. Vanderver was proud of his English.

“Down?” he repeated, drawing down his eyebrows as though to illustrate.

“From her room, I mean.”

“De young lady,” said Vanderver, “iss with you. I have seen her go through dere” — he pointed to the arbor — “fifteen, twenty minutes ago.”

“Yes, I know. But she came back here to get a compact.”

Vanderver was now anxious about his English.

“Please?” he prompted, cupping his hand behind his ear.

“I said she came back here to get a compact. You know. This kind of thing.” Dermot held it up. “She walked back through the arbor—”

“My friend,” said Vanderver with sudden passion, “I do not know if I have understood you. Nobody has come back through this arbor while I am sitting here.”

“But that’s impossible.”

“Please?”

Dermot thought he saw the explanation. “You mean you haven’t been sitting here all the time?”

“My friend,” said Vanderver, taking out a watch and shaking it, “I am sitting here one hour more... more! — where I sit always and smoke my cigar before I dress. Yes?”

“Well, Doctor?”

“I have seen the young lady go through, yes. But I have not seen her come back. I haf not seen nobody. In all dat time the only liffing soul I see on this terrace is the maid which gather up your tea-tray and bring it back here.”

The terrace, always dark in the shadow of the arbor, was growing more dusky.

“Dr. Vanderver, listen to me.” Dermot spoke coldly and sharply; he found Vanderver’s thick-lensed spectacles turning on him with hypnotic effect. “That is not what I mean. I remember the maid going back through the arbor with the tray. But Miss Weatherill was with me then. I mean later. L-a-t-e-r, several minutes later. You saw Miss Weatherill come out through here about ten minutes ago, didn’t you?”

“No.”

“But you must have! I saw her go into the arbor on my side, and I never took my eyes off the entrance. She isn’t in the arbor now; see for yourself. She must have come out here.”

“So!” said Vanderver, tapping the table with magnificent dignity. “Now I tell you something. I do not know what you think has happened to the young lady. Perhaps de goblins ketch her, yes? Perhaps she dissolved to electrons and bust, yes?” Dark blood suffused his face. “Now I will haf no more of this. I settle it. I tell you.” He thrust out his thick neck. “Nobody,” he said flatly, “hass come back through this arbor at all.”

By nine o’clock that night, terror had come to the Hotel Suchard.

Until then Monsieur Gant, the manager, had refrained from summoning the police. At first Monsieur Gant appeared to think that everybody was joking. He only began to gesticulate, and to run from room to room, when it became clear that Betty Weatherill was not to be found either in the hotel or in the grounds. If the testimony were to be believed — and neither Dermot nor Vanderver would retract one word — then Betty Weatherill had simply walked into the arbor, and there had vanished like a puff of smoke.

It was certain that she had not left the arbor by (say) getting out through the vines. The vines grew up from the ground in a matted tangle like a wire cage, so trained round their posts from floor to arch that it would be impossible to penetrate them without cutting. And nowhere were they disturbed in any way. There was not — as one romantic under-porter suggested — an underground passage out of the tunnel. It was equally certain that Betty could not have been hiding in the arbor when Dermot walked through it. There was no place there to hide in.

This became only too clear when the Chinese lanterns were lighted in the greenish tunnel, and Monsieur Gant stood on a stepladder to shake frantically at the vine-walls — with half the domestic staff twittering behind him. This was a family matter, in which everybody took part.

Alys Marchand, in fact, was the backstairs-heroine of the occasion. Alys was the plump waitress who had been sent to fetch fresh tea and sandwiches not fifteen minutes before Betty’s disappearance, but who had not brought them back because of a disagreement with the cook as to what hours constituted feev-o’clock-tay.

Apart from Dermot, Alys had been the last person to see Betty Weatherill in the flesh. Alys had passed unscathed through the arbor. To Monsieur Gant she described, with a wealth of gesture, how she had taken the order for tea and sandwiches from Monsieur Dermot. She showed how she had picked up the big tray, whisking a cloth over its debris like a conjuror. A pink-cheeked brunette, very neat in her black frock and apron, she illustrated how she had walked back through the arbor towards the hotel.

Had she seen Dr. Vanderver on this occasion?

She had.

Where was he?

At the little table on the terrace. He was smoking a cigar, and sharpening a big horn-handled knife on a small whetstone block he carried in his pocket.

“That,” interposed Vanderver, in excellent French, “is a damned lie.”

It was very warm in the arbor, under the line of Chinese lanterns. Vanderver stood against the wall. He seemed less bovine when he spoke French. But a small bead of perspiration had appeared on his forehead, up by the large vein near the temple; and the expression of his eyes behind the thick spectacles turned Andrew Dermot cold.

“It is true as I tell you,” shrieked Alys, turning round her dark eyes. “I told my sister Clothilde, and Gina and Odette too, when I went to the kitchen. He thrusts it into his pocket — quick, so! — when he sees me.”

“There are many uses for knives,” said Monsieur Gant, hastily and nervously. “At the same time, perhaps it would be as well to telephone the police. You are an advocate, Monsieur Dermot. You agree?”

Dermot did agree.

He had been keeping tight hold of his nerves. In fact, he found the cold reason of his profession returning to him; and it was he who directed matters. Instead of bringing back the nightmare, this practical situation steadied him. He saw the issue clearly now. It became even more clear when there arrived, amid a squad of plainclothes men, none other than Monsieur Lespinasse, the juge d’instruction.

After examining the arbor, M. Lespinasse faced them all in the manager’s office. He was a long, lean, melancholy man with hollow cheeks, and the Legion of Honor in his buttonhole. He had hard uncomfortable eyes, which stared down at them.

“You understand,” said Lespinasse, “we appear to have here a miracle. Now I am a realist. I do not believe in miracles.”

“That is good,” said Dermot grimly, in his careful French. “You have perhaps formed a theory?”

“A certainty,” said Lespinasse.

The hard uncomfortable eyes turned on Dermot.

“From our examination,” said Lespinasse, “it is certain that Mlle. Weatherill did not leave the arbor by any secret means. You, monsieur, tell one story.” He looked at Vanderver. “You, monsieur, tell another.” He looked back at Dermot. “It is therefore evident that one of you must be telling a lie.”

Vanderver protested at this.

“I remind you,” Vanderver growled, with a significant look, “that it will be unwise for you to make mistakes. As an acting representative of His Majesty the King of Sylvania, I enjoy immunities. I enjoy privileges—”

“Diplomatic privileges,” said Monseur Lespinasse. “That is no concern of mine. My concern is that you do not break the civil law.”

“I have broken no law!” said Vanderver, purple in the face. “I have told no lie!”

The juge d’instruction held up his hand.

“And I tell you in return,” he said sharply, “that either your story or Monsieur Dermot’s must be untrue. Either the young lady never went into the arbor, in which case Monsieur Dermot is telling a falsehood. Or else she did go in, and for some reason you choose to deny that you saw her come out. In which case—” Again he held up his hand. “It is only fair to warn you, Dr. Vanderver, that Miss Weatherill told me you might try to kill her.”

They could hear a clock ticking in the overcrowded room.

“Kill?” said Vanderver.

“That is what I said.”

“But I did not know her!”

“Evidently she knew you,” answered M. Lespinasse. His sallow face was alive with bitterness; he fingered the rosette in his buttonhole. Then he took a step forward. “Miss Weatherill several times came to me at the prefecture of police. She told me of your — murderous activities in the past. I did not choose to believe her. It was too much of a responsibility. Responsibility! Now this happens, and I must take the responsibility for it at least. One more question, if you please. What have you to say to the maid’s story of the horn-handled knife?”

Vanderver’s voice was hoarse. “I never owned such a knife. I never saw one. I call you a son of—”

“It will not be necessary to finish,” said the juge d’instruction. “On the contrary, we shall finish.” He snapped his fingers, and one of the plainclothes men brought into the room an object wrapped in a newspaper.

“Our search of the arbor,” continued M. Lespinasse, “was perhaps more thorough than that of Monsieur Gant. This was found buried in the sand floor only a few feet away from where monsieur was sitting.”

There were more than damp stains of sand on the bright, wafer-thin blade in the newspaper; there were others. Monsieur Lespinasse pointed to them.

“Human blood,” he said.

At eleven o’clock Andrew Dermot was able to get out of the room.

They told him afterwards that he had made an admirable witness; that his replies had been calm, curt, and to the point; and that he had even given sound advice on details of legal procedure, contrasting those of England with those of the present country.

He did not remember this. He knew only that he must get out into the air and stop himself from thinking of Betty.

He stood on the front terrace of the hotel, as far removed as possible from the arbor in whose floor the knife had been buried. Half a mile away the lights of the principal street in the town, the Promenade des Francais, twinkled with deathly pallor. A cool wind swept the terrace.

They took Vanderver down the front steps and bundled him into a car. There was a chain round Vanderver’s wrists; his legs shook so that they had to push him up into the car. The car roared away, with a puff of smoke from the exhaust — carbon monoxide, which meant death — and only the juge d’instruction remained behind searching Vanderver’s room for some clue as to why a sudden, meaningless murder had been done at dusk beside a commonplace hotel.

Andrew Dermot put his hands to his temples, pressing hard.

Well, that was that.

He sat down on the terrace. The little round tables had red tops, and the color did not please him, but he remained. He ordered brandy, which he could not taste. The brandy was brought to him by the same underporter who had suggested an underground passage in the arbor, and who, agog, seemed to want to entertain him with speculations about motives for murder. Dermot chased him away.

But if Betty had to go — “go” was hardly the word for that — where was the sense in it? Why? Why? Vanderver was presumably not a homicidal maniac. Besides, all Dermot’s legal instincts were bewildered by so clumsy a crime. If Vanderver were guilty, why had he from the first persisted in that unnecessary lie of saying Betty had never come out of the arbor? Why hadn’t he simply faded away, never professing to have seen anything at all? Why thrust himself at that entrance as though determined to ensure suspicion for himself?

What Dermot had not permitted himself to wonder was where Betty herself might be.

But suppose Vanderver had been telling the truth?

Nonsense! Vanderver could not be telling the truth. People do not vanish like soap-bubbles out of guarded tunnels.

Presently they would be turning out the lights here on this windy, deserted terrace. The Hotel Suchard was ready, in any case, to close its doors for the winter; it would close its doors very early tonight. Behind him, in lighted windows, glowed the lounge, the smoking-room, the dining-room where he had first seen Betty. The head porter, his footsteps rapping on hardwood, darkened first the dining-room and then the lounge. Dermot would have to go upstairs to his room and try to sleep.

Getting to his feet, he walked through the thick-carpeted hall. But he could not help it. He must have one more look at the arbor.

It was veritable tunnel now: a black shape inside which, for twenty yards, Chinese lanterns glowed against the roof. The sand was torn where the knife had been dug out. Near that patch, two shovels had been propped against the wall in readiness for deeper excavations next morning. It was when he noted those preparations, and realized what they meant, that Dermot’s mind turned black; he had reached his lowest depth.

He was so obsessed by it that he did not, at first, hear footfalls on the tiled terrace. He turned round. Two persons had come out to join him — but they came by different windows, and they stopped short and stared at each other as much as they stared at him.

One of these persons was M. Lespinasse, the juge d’instruction.

The other was Betty Weatherill.

“And now, mademoiselle,” roared Lespinasse, “perhaps you will be good enough to explain the meaning of this ridiculous and indefensible trick?”

M. Lespinasse, his cheek-bones even more formidable, was carrying a briefcase and a valise. He let both fall.

“I had to do it,” said Betty, addressing Dermot. “I had to do it, my dear.”

She was not smiling at him. Dermot felt that presently, in the sheer relief of nerves, they would both be shouting with laughter. At the moment he only knew that she was there, and that he could touch her.

“One moment,” said Lespinasse, coldly interrupting what was going on. “You do well, Monsieur Dermot, to demand an explanation—”

“But I don’t. So long as she’s—”

“—of this affair.” The juge d’instruction raised his voice. “I can now tell you, in fact I came downstairs to tell you, how Miss Weatherill played this trick. What I do not know is why she did it.”

Betty whirled round. “You know how?”

“I know, mademoiselle,” snapped the other, “that you planned this foolishness and carried it out with the assistance of Alys Marchand, who deserves a formidable stroke of the boot behind for her part in the affair. When I found Alys ten minutes ago capering round her room waving a packet of thousand-franc notes, her behavior seemed to call for some explanation.” He looked grim. “Alys was very shortly persuaded to give one.”

Then he turned to Dermot.

“Let me indicate what happened, and you shall confirm it! Miss Weatherill asked you to meet her here, even specifying the table you were to occupy, and said she would arrive after tea?”

“Yes,” said Dermot.

“At half-past five she came through the arbor — first making certain that Dr. Vanderver was on the terrace in the place he always occupied, every day, to smoke a cigar at that hour?”

“I... yes.”

“Miss Weatherill was easily persuaded to have a fresh cup of tea?”

“Well, I asked her to.”

“The waitress, Alys, was then pottering round for no apparent reason among otherwise deserted tables?”

“She was.”

“You gave the order to Alys,” said Monsieur Lespinasse grimly. “She picked up your tray — a big tray — whisking over it a large cloth to cover the dishes? Just as we later saw her do?”

“I admit it.”

“Alys then walked away from you through the arbor. As she did so,” leered Lespinasse, so intent that he made a face, “Miss Weatherill distracted your attention by getting a light for her cigarette. And kept your attention fixed on herself by dropping the cigarette, and pretending an agitation she did not feel.”

Dermot gave a quick look at Betty. Whatever else this might be, it was not a hoax or a joke. Betty’s face was white.

“Miss Weatherill held your attention,” said Lespinasse, “so that Alys could slip back out of the arbor unnoticed. Alys did not really go through the arbor at all! Carrying the tray, she merely darted round the side of the arbor and returned unseen to the hotel by another way.

“Miss Weatherill was then ready to play the rest of the comedy. ‘Discovering’ the loss of her compact, she enters the arbor. Halfway up, in the darkness, is lying a stage-property these two have already left there. This is another tray: like the first, and covered with a cloth. But this cloth does not cover dishes. It covers—”

Monsieur Lespinasse broke off.

He looked flustered and dishevelled, but in his wicked eye there was a gleam of admiration.

“Monsieur Dermot, I tell you a psychological truth. The one person in this world whose features nobody can remember are those of a waitress. You see her at close range; yet you do not see her. Should you doubt this, the next time in your abominable London you go into a Lyons or an A.B.C., try calling for your bill in a hurry and see if you can identify the particular young lady who served you with a cup of tea. I know it. So did Miss Weatherill.

“She was already wearing a thin black frock under her white one. The tray in the arbor contained the other properties by which a blonde is changed into a brunette, white stockings and shoes change to black, a tanned complexion is heightened to a vivid ruddiness. It was the clumsiest possible disguise because it needed to be no more. Dr. Vanderver never glanced twice at the black-clad figure in cap and apron who walked out of the arbor carrying a tray. He saw no black wig; he saw no false complexion; he saw nothing. In his mind there registered, ‘waitress-has-passed’: no more. Thus Miss Weatherill, inexpertly got up as Alys, passed safely through the dense shadow which the arbor casts on the terrace — carrying before her the tray whose cloth nearly hid the discarded white dress, stockings, and shoes.”

The juge d’instruction drew a deep, whistling breath.

“Very well!” he said. “But what I wish to know is: why?”

“You don’t see it even yet?” asked Betty.

“My deepest apologies,” said Lespinasse, “if I am dense. But I do not see it. You cannot have liked cutting yourself so that you might get real blood to put on the knife you buried. But why? How does all this nonsense help us, when Dr. Vanderver has committed no crime?”

“Because he’s Embassy,” answered Betty simply.

“Mademoiselle?”

“He has diplomatic immunity,” said Betty. “The government can’t search him; can’t even touch him. And so, you see, I had to get him arrested by the civil authorities so that his papers could be searched.”

She turned to Dermot.

“Derry, I’m sorry,” she went on. “That is, I’m sorry I’m not quite the candid-camera schoolmistress burbling to high heaven that I pretended to be. But I want to be just that. I want to enjoy myself. For the first time in all my life, I’ve enjoyed myself in the last month. What I mean is: I want to be with you, that’s all. So, now that I’m chucking the beastly job—”

Monsieur Lespinasse swore softly. After remaining rigid for a moment, he picked up the brief-case and the valise he had dropped.

Both were in green leather stamped in gold with the royal arms of Sylvania.

“—and of course,” Betty was saying almost wildly, “the fellow’s name wasn’t ‘Dr. Vanderver,’ and he’s no more a neutral than I am. Only he’d got that job on forged credentials, and he was safe. So I had to keep telling the juge d’instruction I suspected him of being a murderer. His real name is Karl Heinrich von Arnheim; and when Sir George — you know to whom I refer, Monsieur Lespinasse — asked me to go after him—”

Monsieur Lespinasse could not break the lock of the brief-case. So he opened a wicked-looking knife of his own to slit the leather; and so he found the secret.

“The English,” he said, “are not bad.” He waved the knife, which glittered against the light from the windows. “Dr. Vanderver will not, I think, leave the police station after all.” He swept Betty Weatherill a profound bow. “The complete plans,” he added, “of the underground fortifications whose fall would break the whole line of defense along this front.”