Back in his office, Mason held a hurried conference with Jackson, his law clerk, Della Street and Paul Drake.
“Find me some authority,” he said to Jack, “which even squints at the doctrine that hearsay evidence may be brought out on cross-examination to show the reason which actuated the witness... There must be some authority somewhere — such, for instance, as a question, Didn’t you go to a certain place, because so-and-so told you that such-and-such was the case?”
Jackson nodded, vanished into the law library.
Mason, frowning, said, “Unless I can drag that clock in on cross-examination, I’m not going to get it in. And the way things look right now, I’m not going to get it in on cross-examination.”
“Did you think you could?” Della Street asked.
Mason said, “I’m sparring for time. Burger intended to rest his case. Judge Canfield would then have given me until two o’clock to put on my case. As it is now, we’ll start arguing at two o’clock. I can talk for ten or fifteen minutes. Then let’s suppose Judge Canfield rules against me, and then Burger rests his case. The Judge will then give me another continuance until tomorrow morning before I have to start putting on my case. I’ll gain that much... Damn it, Paul, that clock means something, and yet I can’t even get it into evidence unless I can find out what it means.”
“We can’t get anywhere with Mrs. Payson,” Drake said. “She’s interested in astrology, but she’s interested in a lot of other things. Astrology, it seems, doesn’t have so much to do with astronomy, and like lots of women who talk about the signs of the zodiac, she doesn’t know a damn thing about the stars themselves.”
“You’re certain?”
“Yes. I’ve pumped her.”
“She might have been holding out on you.”
“I don’t think so.”
Mason said, “Hang it, Paul. That clock wasn’t set on sidereal time just as an accident. It wasn’t—” He broke off abruptly.
“What’s the matter?” Drake asked.
Mason said, “An idea, that’s all... but — shucks, Paul!”
Mason picked up the telephone, said to the girl at the switchboard, “Gertie, get me the county clerk’s office. I want the deputy who has charge of exhibits in the case of People versus Hardisty and Macon. I’ll wait on the phone.”
Mason held the telephone, his fingertips drumming the desk. After a few moments he said, “Hello. This is Perry Mason talking. That alarm clock which was introduced into evidence... Is it still running? It is. How fast is it running?... Check that accurately, will you? Let me have the exact time shown on it at a certain precise moment.”
Mason took out his watch, laid it on the desk in front of him, said, “Okay, let me have it right now.”
He marked down the figures on a pad of paper, frowned thoughtfully at them, then said after a moment, “Yes, that’s all. Thank you.”
He dropped the receiver back into place, said, “That’s strange.”
“What is?” Della Street asked.
“In the first place,” Mason said, “that’s a twenty-four-hour clock. We can count on somewhere around thirty-six hours to a winding. It will vary somewhat, depending upon the condition of the spring and the make of the clock. However, it’s still running strong. That indicated it was wound up shortly before it was discovered. But the interesting thing is that the clock hasn’t gained a minute since yesterday.”
“Well?” Della Street asked.
“Sidereal time,” Mason said, “is almost exactly four minutes faster each day. It lacks just two or three seconds of that. It—” Abruptly he threw back his head and began to laugh.
“What is it?” Della Street asked.
Mason’s laughter became uproarious. “The joke,” he said, “is on me. I’m laughing at myself. We baited a trap and then walked into it ourselves.”
“I don’t get you,” Drake said.
Mason said, “It goes back to the quotation about the engineer being hoist with his own petard... Della, tell Jackson not to make any further investigation. We won’t need those authorities... Now give me half an hour to get my thoughts straightened out and we’ll walk into court and give Mr. Hamilton Burger and his fresh assistant, Mr. Thomas L. McNair, a jolt they’ll remember as long as they live! The solution of this whole mystery has been staring me right in the face, and I’ve been so blind I couldn’t see it!”