'Yes.'

'Opportunity?' he said.

'No one can remember what they were doing the day Angela Brickell disappeared.'

'Except the murderer,' he observed. 'What about opportunity on the day Mr Goodhaven fell through the floor?'

'Someone was there to drive his car away- no fingerprints, I suppose?'

'Gloves,' he said succinctly. 'Too few of Mr Goodhaven's prints are still there. No palm print on the gear lever, for instance. I don't know if we'd have worried about that if we'd thought he'd done a bunk. It was a cold day, after all. He might have worn gloves himself.'

'You might have guessed at collusion,' I suggested.

'Did you ever consider police work?'

'Not good at that sort of discipline.'

'You don't like taking orders, sir?'

'I prefer giving them to myself.'

He smiled without criticism. 'You'd be no good in uniform.'

'None at all.'

He was ent.i.tled, I supposed, to his small exploratory excursion around my character; and if he himself, I thought, had been wholly fulfilled by uniform, he would still be in it.

Perkin in his overalls appeared in the open doorway, hovering.

'Is Mackie over here?' he said. 'I can't find her.'

'In the kitchen with Tremayne,' I said. 'Thanks.' He swept a gaze over Doone and the plank and said with irony, 'Sorting it out, then?'

Doone said a shade heavily, 'Mr Kendall's always helpful,' and Perkin made a face and went off to join Mackie.

'About Harry's car,' I said to Doone. 'There must have been just a small problem of logistics. I mean, perhaps our man parked his own car in Reading station car park, then took a train to Maidenhead station and a bus from there to near the river, and went on foot from there to the boatyard- wouldn't that make sense?'

'It would, but so far we haven't found anyone who noticed anything useful.' 'Car park ticket?'

'There wasn't one in the car. We don't know when the car arrived in the car park. It could have been parked somewhere else on Wednesday and repositioned when our man discovered Mr Goodhaven was still alive.'

'Mm. It would mean that our man had a lot of time available for manoeuvring.'

'Racing people do have flexible hours,' he observed, 'and they mostly have free afternoons.'

'I don't suppose there's a hope that my jacket and boots were still in the car?' I asked.

'No sign of them. Sorry. They'll be in a dump somewhere, shouldn't wonder.' He was looking round the room again, and this time revealed his purpose. 'About those guide books of yours, I'd like to see them.'

They were in the family room. I went to fetch them and returned with only three I'd found, Jungle, Safari and Ice. The others, I explained, could be anywhere, as everyone had been reading them.

He opened Jungle and quickly flipped through the opening chapters, which were straightforward advice for well-equipped jungle holidays: 'Never put a bare foot on the earth. Shower in slip-ons. Sleep with your shoes inside your mosquito netting. Never drink untreated water- never brush you teeth with it- don't wash fruit or vegetables in it, avoid suspect ice-cubes.'

' "Never get exhausted"!' Doone said aloud. 'What sort of advice is that?'

'Exhausted people can't be bothered to stick to life-saving routines. If you don't drive yourself too hard you're more likely to survive. For instance, if you've a long way to go, it's better to get there slowly than not at all.'

'That's weak advice,' he said, shaking his head.

I didn't argue, but many died from exhaustion every year through not understanding the strengths of weakness. It was better to stop every day's travel early so as to have good energy for raising a tent, digging an igloo, building a platform up a tree. Dropping down exhausted without shelter could bring new meaning to the expression 'dead tired'.

' "Food," ' Doone read out.' "Fishing, hunting, trapping." ' He flicked the pages. ' "In the jungle, hang fishhooks to catch birds. Don't forget bait. You always need bait."' He looked up. 'That envelope was bait, wasn't it?'

I nodded. 'Good bait.'

'We haven't found it. That water's like liquid mud. You can't see an inch through it, my men say.'

'They're right.'

He stared for a second. 'Oh, yes. I'd forgotten you'd been in it.' He went back to the book. ' "It's possible to bring down game with a spear or a bow and arrow, but these take considerable practice and involve hours spent lying in wait. Let a trap do the waiting- " ' He read on. ' "The cla.s.sic trap for large animals is a pit with sharpened staves pointing upwards. Cover the pit with natural-looking vegetation and earth, and suspend the bait over the top." ' He looked up. 'Very graphic ill.u.s.trations and instructions.'

'Afraid so.'

Eyes down again to the book, he went on, ' "All sharpened staves for use in traps (and also spears and arrows) can be hardened to increase their powers of penetration by being charred lightly in hot embers, a process which tightens and toughens the wood fibres." ' Doone stopped reading and remarked, 'You don't say anything about sharpening old bicycle frames and railings.'

'There aren't many bicycle frames in the jungle. Er- were they sharpened?'

He sighed. 'Not artificially.' He read on.' "If digging or sc.r.a.ping out a pit is impracticable because of hard or waterlogged ground, try netting. Arrange a net to entangle game when it springs the trap. To make a strong net you can use tough plant fibres- " ' He silently read several pages, occasionally shaking his head, not, I gathered, in disagreement with the text, but in sorrow at its availability.

' "How to skin a snake," ' he read. 'Dear G.o.d.'

'Roast rattlesnake tastes like chicken,' I said.

'You've eaten it?'

I nodded. 'Not at all bad.'

' "First aid. How to stop heavy bleeding. Pressure points- To close gaping wounds, use needle and thread. To help blood clot, apply cobwebs to the wound." Cobwebs! I don't believe it.'

'They're organic,' I said, 'and as sterile as most bandages.'

'Not for me, thanks.' He put down Jungle and flipped through Safari and Ice. Many of the same suggestions for traps appeared in all the books, modified only by terrain.

' "Don't eat polar bear liver," ' Doone read in amazement, ' "it stores enough vitamin A to kill humans." ' He smiled briefly. 'That would make a dandy new method for murder.'

First catch your polar bear-

'Well, sir,' Doone said, laying the books aside, 'we can trace the path of ideas about the trap, but who do you think put them into practice?'