right place and steal the damned stuff ready-made just as they did here this afternoon?’
Ryder said: ‘How is it all stored?’
‘In ten-litre steel bottles each containing seven kilograms of U-235, in the form of either an oxide or metal, the oxide in the form of a very fine brown powder, the metal in little lumps known as “broken buttons”. The bottles are placed in a cylinder five inches wide that’s braced with welded struts in the centre of a perfectly ordinary fifty-five-gallon steel drum. I needn’t tell you why the bottles are held in suspension in the airspace of the drum–stack them all together in a drum or box and you’d soon reach the critical mass where fissioning starts.’
Jeff said: ‘This time it goes bang?’
‘Not yet. Just a violent irradiation which would have a very nasty effect for miles around, especially on human beings. Drum plus bottle weighs about a hundred pounds, so is easily moveable. Those drums are called “bird-cages”, though Lord knows why: they don’t look like any bird-cage I’ve ever seen.’
Ryder said: ‘How is this transported?’
‘Long distance by plane. Shorter hauls by common carrier.’
‘Common carrier?’
‘Any old truck you can lay your hands on.’ Ferguson sounded bitter.
‘How many of those cages go in the average truck shipment?’
‘That hi-jacked San Diego truck carries twenty.’
‘One hundred and forty pounds of the stuff. Right?’
‘Right.’
‘A man could make himself a fair collection of nuclear bombs from that lot. How many drums were actually taken?’
‘Twenty.’
‘A full load for the van?’
‘Yes.’
‘So they didn’t touch your plutonium?’
‘More bad news, I’m afraid. When they were being held at gunpoint but before they were locked up some of the staff heard the sound of another engine. A diesel. Heavy. Could have been big–no one saw it.’ The telephone on his desk rang. He reached for it and listened in silence except for the occasional ‘who?’, ‘where?’ and ‘when?’ He hung up.
‘Still more bad news?’ Jablonsky asked.
‘Don’t see it makes any difference one way or another. The hi-jacked van’s been found. Empty, of course, except for the driver and guard trussed up like turkeys in the back. They say they were following a furniture van round a blind corner when it braked so sharply that they almost ran into it. Back doors of the van openedand the driver and the guard decided to stay just where they were. They say they didn’t feel like doing much else with two machine-guns and a bazooka levelled six feet from their windscreen.’
‘An understandable point of view,’ Jablonsky said. ‘Where were they found?’
‘In a quarry, up a disused side road. Couple of young kids.’
‘And the furniture van is still there?’
‘As you say, Sergeant. How did you know?’
‘Do you think they’d have transferred their cargo into an identifiable van and driven off with it? They’d have a second plain van.’ Ryder turned to Dr Jablonsky. ‘As you were about to say about this plutonium–’
‘Interesting stuff and if you’re a nuclear bomb-making enthusiast it’s far more suitable for making an atom bomb than uranium although it would call for a greater deal of expertise. Probably call for the services of a nuclear physicist.’
‘A captive physicist would do as well?’
‘What do you mean?’
‘They–the villains–took a couple of visiting physicists with them this afternoon. From San Diego and Los Angels, I believe they were.’
‘Professor Burnett and Dr Schmidt? That’s a ludicrous suggestion. I know both men well, intimately, you might say. They are men of probity, men of honour. They’d never co-operate with the blackguards who stole this stuff.’
Ryder sighed. ‘My regard for you is high, Doctor, so I’ll only say that you lead a very sheltered life. Men of principle? Decent men?’
‘Our regard is mutual so I’ll just content myself with saying that I