putting him on the list is purely vindictive if you ask me. And the IRA's not much better - I can't help thinking that they leaked this to us in the first place just to screw us up in knots.' Paul shook his head. 'Which, of course, is what it's doing.'
He shook his head again, and Frances observed him with a mounting sense of disquiet. This wasn't the cool analysis that accompanied proper security, it was more like an acceptance of the inevitable, the sort of fatalism she imagined soldiers in the very front line must have on the eve of an enemy offensive.
But if that was so then the doubling of the targets
didn't make sense.
'But Paul - d'you mean to say we've let two people on the list get together in the same place?'
'Three, actually.'
'No.' Paul appeared to concentrate on the police car ahead. 'The Lord-Lieutenant will be there, and he was General Officer Commanding in Ulster a few years back. Now he's one of the top advisers to the Minister's opposite number on the shadow cabinet - which puts him right at the head of the list, alongside the Minister himself in fact. Because he's a smart fellow.'
Frances found herself staring in the same direction, at the flashing hazard lights of the police car, as they overtook a clot of traffic which had formed behind two juggernaut lorries racing each other up the motorway. With Michael O'Leary on the loose it was nothing short of insanity to assemble three prime targets on one spot; or, at least, on one spot away from the maximum security zone of Westminster and Whitehall where such assemblies were acceptable.
'I know what you're thinking,' said Paul.
But Frances was by no means sure what she was thinking. There was obviously some sort of emergency, no matter what Paul had said to the contrary. It was difficult not to jump to the conclusion that it was directly related to the insanity - the irresistible bait which some fool had dangled in front of O'Leary. Perhaps they were panicking now because they'd only just realised what they'd done.
'Huh!' She simulated contempt. If Paul thought he knew what she was thinking she had to encourage him to think aloud.
He gave a quick nod. 'That's the way I feel, exactly. But then I thought - North Atlantic, '43-'44 - U-boats versus escorts - same problem, same answer.'
'North Atlantic - ?' Frances caught herself just in time. Not so very long before Paul Mitchell had been a budding young military historian, and one hangover from that lost career was his irritating habit of trying to reduce every situation to some obscure military analogy which could then be solved by the application of Clauswitz or Liddell- Heart. But this time, instead of deriding his theories, she could use them to establish what was really going on.
'I don't see how the North Atlantic comes into things, Paul. Enlighten me.'
'It's simple. The Atlantic is very big and a U-boat is very small.'
'And it spends most of its time underwater anyway.'
He looked at her quickly. 'You've got the point?' He sounded a little disappointed.
'No. But I thought that was how submarines behaved. Go on.'
'An ...' He brightened. 'So of course they're awfully difficult to find, unless you're lucky.'
'I thought we had radar for that.'
'Don't complicate matters. That isn't the point.'
'Sorry.' Frances curbed her impatience.
'The point is that you don't have to find a submarine. Because if it's any good it's going to find you - you being a convoy.' Again he glanced at her quickly. 'And don't start telling me it's the convoy's job to avoid the U-boat, I know that. I'm simplifying things, that's all.' He turned back to the road. 'There's no avoiding O'Leary, anyway.'
'I see. So O'Leary's a U-boat, and we're the convoy escorts - and we just sit around and wait for him to turn up?' Frances frowned at the banality of the image. 'That doesn't seem very profound, either as a metaphor or as a piece of naval tactics.'
'Uh-huh? Well, that's where you're wrong ... In fact, it's a typical armchair critic's mistake. Everything's simple when you know how to do it.'
His patronising tone galled Frances. 'Well, I don't pretend to be an expert on naval tactics, Paul.'
'You don't have to be. It's just elementary geometry: double the size of the convoy and you don't double its circumference - it took the admiralty years to discover that allegedly simple fact.'
'So what?'
He gave her a pitying look. 'So you haven't actually doubled the size of the target.
But you have doubled the number of escorts... We've trebled the target on the university campus this afternoon - but as they're in the same place we can concentrate three times as many counter-terrorism experts in the same place. The mathematics are more favourable for guarding human beings than they are for ships, so we can put more than half our people on the look-out for O'Leary. They're the equivalent of what the Navy used to call 'hunter-killer groups' attached to the convoys - so instead of just guarding the bloody targets for once we've actually got the manpower to hunt the bastard as soon as he comes in range.'
'Always supposing that he chooses to oblige you by turning up.
This time it was a half-grin. 'Oh - he' s coming right enough.'
Frances started to add up the facts. If Paul was so sure that an attempt was going to be made then there was inside information, and it would probably have come from the IRA itself ... And it was undeniably true that there was always a chronic shortage of skilled manpower - and womanpower - because so much of it was needed for