Knife Edge

1.10 P.M.

The contents of the plastic tray didn't look like much.

A few blackened, twisted pieces of plastic, some wire, a portion of battery, fragments of glass and other items which resembled little more than drops of solidified wax.

Detective Sergeant Colin Mason leaned on the work top, peering at the stuff in the tray, occasionally sucking in a deep breath. Sometimes peering at the other two men in the room.

John Fenton and Peter Draper were members of the bomb squad. Both in their late thirties, both dressed in black uniforms, they even looked alike. The same full features, same slim build. The only difference immediately apparent was that Fenton was much taller than his companion. A good six inches, Mason guessed.

Draper was chewing gum, rolling the balled-up silver foil which the stick had been wrapped in beneath his finger as if he was trying to shape it into a perfect sphere.

'It was Semtex all right,' Fenton said finally. 'I'd say about ten pounds, maybe less.'

'Are you sure?' Mason demanded.

'About the explosive or the weight?' Fenton asked.

'It was definitely C4,' Draper added. 'We ran acetone tests on the debris. The spectrometry confirmed it.'

'Hidden inside a video cassette case as far as we can tell,' Fenton informed the policeman.

'How the hell did Neville manage that?' Mason wanted to know.

'Easy,' Fenton said. 'He took the cassette out and put the Semtex in the box instead.'

'You know what I mean,' Mason snapped. 'How long could it have been there?'

'Two hours, two days, two weeks. It's impossible to say,' Draper said. 'He'd have needed to be sure it was in a case that wouldn't be removed before he wanted to detonate it. Something he was sure no one would buy.'

Fenton just shrugged.

'And how was it detonated?' Mason persisted.

'Battery,' Fenton said, pointing to a portion of a Duracell with the end of his pencil. 'We found this at the scene. All high explosives need to be started by a separate detonating blast. With portable bombs like this one Neville used, it's nearly always batteries.'

'Some use low explosives as the detonator,' Draper added.

'What the fuck are low explosives?' Mason enquired.

'Stuff like black powder or smokeless,' Draper explained, still chewing. 'The kind of powder used in cartridges. Natural gas is a low explosive. Mixtures of air, even petrol. Low explosive just burns unless it's activated and when it is, the explosion created is totally different from blasts caused by high explosive. The low stuff creates a sort of throwing action. High explosive shatters its target. Mind you, it does detonate at a rate of up to five thousand feet a second, so you can see the difference.' He smiled smugly.

'How would Neville have set it off?' Mason asked.

'I told you, the detonator was a battery,' Fenton began.

'I mean, by remote control. What?'

The two bomb squad men looked at each other.

'An electronic signal of some kind, I'd say,' Fenton offered.

His companion nodded in agreement.

'It must have had a fair old range on it,' Fenton continued.

'And been attuned to that device specifically,' Draper added.

'Keep it simple, will you?' Mason snapped.

'With an electronic detonator, if the bomber isn't quite sure what he's doing, the bomb could be set off prematurely by any kind of electronic emission. A TV remote control. The signal from a radio. Even too much neon.'

'Neville obviously know his stuff,' Draper said.

'Like we didn't already know,' Mason grunted. 'What about the other bombs he's planted or that he intends to detonate. Could they be the same?'

'It's very likely,' Draper explained. 'Most bombers tend to stick to the same kind of device. They stick to what they know. Chances are, Neville's other bombs are the same.'

'All seven of them,' Mason muttered.

'When's the next one due?' Draper wanted to know.

Mason looked at his watch and sucked in a deep breath.

'About twenty minutes,' he said quietly. 'Christ alone knows where.'