‘About a hundred yards from the factory there’s a side street called Brag Alley. I’ve marked it on the map I’m giving you. Lift the manhole at the far end and you’ll find yourself in a tunnel about three feet in diameter that carries the Electricity Board main cables. You’ll know when you’ve reached Chatsworth Steel because they’ve been obliging enough to paint it on the wall. There’s a single-course brick wall between you and the cellars of the office block. If it takes you longer than ten minutes to get through that I’ll eat my hat.’

‘What about the alarm system?’

‘I’m coming to that. When you get into the cellar you’ll find a battery of fuse boxes on the far wall and they’re all numbered. I’ve numbered the ones you’ll have to switch off in your instructions, but the most important thing to remember is to cut the green cable you’ll find running along the skirting board. It looks innocent enough, but it controls an alarm feeder system in case the others fail.’

‘Are the vaults on the same level?’

‘That’s right – at the far end of the corridor.’

‘What about night guards?’

‘They only have one.’ Morgan raised his eyebrows incredulously and Vernon grinned. ‘I told you they’d installed every gadget known to man. The whole place is rigged for closed-circuit television, which is operated by one man from a control room off the main entrance hall. The moment you leave that cellar and walk down the passage you’ll be giving a command performance. All he does is lift the ’phone and the coppers are all over you before you know it.’

‘Okay,’ Morgan said. ‘The suspense is killing me. How do we sort that one out?’

‘They run a three-shift system and our man takes over at eight. He always stops in at a little café near the main gates for sandwiches and a flask of coffee. On Wednesday night he’ll get more than he bargained for.’

‘Something in his coffee?’

Vernon grinned. ‘Simple when you know how.’

Morgan looked dubious. ‘What if he hasn’t had a drink by the time we arrive? We’d be in dead lumber.’

‘I’ve thought of that. You won’t break in till midnight. That gives him four hours. If he hasn’t had a drink by then, he never will.’

There was a long silence as Morgan sat staring into the distance, a slight frown on his face. After a while he sighed and shook his head.

‘I’ve got to give it to you, Max. It’s good – it’s bloody good.’

‘See you tomorrow night then,’ Vernon said calmly and passed him the briefcase. ‘Everything you need is in there. Your train leaves at five o’clock. You’ve got twenty minutes.’