Mrs H. works at home (on dust sheet in dining-room) painting views of Henley by hand onto plates, jugs, boxes; all china. Very quick, very good (to my eyes), nice pictures. They go off to be glazed, she said, then sell in local shops. Reasonably paid, she says. (What's reasonable? She says her work was to be seen as a hobby. Mr D. refers to it in that way.)

Mrs H. works alone nearly every day, no alibis for Friday or Tuesday. Sometimes drives into Henley to shop, no regular pattern. Mrs H. has white Cavalier, clean, no dents.

No children at home. Daughter shares flat with friends near art school (more expense).

Mrs H. ultra-loyal to Mr D. Says my enquiries unnecessary. Says it's ridiculous to suppose Mr D. would attack his father. Out of the question. (My opinion, she wasn't too sure.) They need more cash badly (my opinion).

Mrs H. mostly shares Mr D.'s opinion of Mr Ian, but doesn't seem to dislike him personally. End of enquiry.

On Friday morning, I called in on a public library and looked up "explosives" in encyclopaedias. Ammonium nitrate was there, also the proportion of fertiliser to diesel oil needed, also the formula for relating volume to kilos. The knowledge was available to anyone who sought it.

On Friday after lunch I went to the Marblehill Golf Club and found Donald in the club room placating a foursome who had arrived late and missed their game.

"Go over to the house," he said when he saw me. "I can't talk here."

He turned decisively back to the problem in hand and I did what I was told, like a good little brother.

Helen was resigned more than annoyed to see me. "Ferdinand said you would come, and we had the police here yesterday. Not that we could tell them anything, or you either."

She was wearing a painter's smock over jeans and looked dressed by Dior. She took me into the sitting-room and pointed to a chair, and with unconscious grace sat herself half-on, half-off a polished table, raising her wrists to keep her paint-smudged hands away from the furniture.

Donald came bustling in, telling me he could give me ten minutes. "Don't see what you can do," he said. "Leave it to the police."

"What did they ask you?"

"About Fred blowing up the tree stump. I said yes, of course we'd been there. Helen and I weren't then married. It was the first time she'd met Malcolm, she was staying the weekend."

"Saturday morning," she said, nodding. "The gardener came in specially to blow up the tree trunks. Not something one would forget, seeing him knocked flat. I took a photograph of the tree roots afterwards. It's still in one of our albums."

"And the time-switch clocks, do you remember those?" I asked.

"Naturally," Donald said. Helen added, "Dear Thomas made two for our boys for their birthday once, when they could just tell the time." She had said Dear Thomas, I noticed, as if she had meant it, not as Berenice said it. "They got lost in one of our moves."

"Where's Malcolm?" Donald asked brusquely.

"I don't know."

"You're lying," he said, but for once I wasn't. Malcolm and Ramsey Osborn had left the Osborn residence, according to the female voice on the line the evening before, and had given her no number at which they could be reached. I could try again tomorrow, she said. Mr Osborn should have let her know by then; he usually did.

"Did either of you," I asked, "trace Malcolm to Cambridge the weekend he was put in the car?"

I hadn't expected any answer but negative, but the question came at them unexpectedly and Helen practically jumped.

"Did you?" I said to her.

"No, of course not," Donald said quickly. "We had no way of knowing he would go to Newmarket Sales, if that's what you're inferring."

"The hotel at Cambridge said three people – two men and a woman – had asked if Malcolm was staying there," I said. "One was Norman West, who were the others? I'm not saying you went to Newmarket Sales, just did one of you trace Malcolm?"

They looked at me glumly. Then Helen said,

"I suppose so."

"Why?" I asked.

Donald cleared his throat. "I needed his signature on a guarantee."

"Go on, what guarantee?"

"For a temporary bank loan." He swallowed. "I thought he might…"

"We had to have the money in a hurry," Helen said. "The bank manager told Donald we could borrow it if Malcolm would guarantee it. Then we couldn't get hold of Malcolm. We had to think where he might be, and he's always going to Cambridge. Donald and I just talked about it, guessing, wondering… And then, well, Donald went over to the club house and I just picked up the AA book and found those hotels in Cambridge, and without really believing in it I tried two… only two… and he was there, at the second. When Donald came home I told him and the extraordinary thing was, he'd had the same idea and got the same result." She paused. "We were pretty desperate, you see." "Don't say that," Donald said. "'Desperate' gives the wrong picture."

"What did you need the money for?" I asked.

They looked at each other, foreheads wrinkled in worry. Finally, reluctantly, but as if coming to a decision, Donald said, "We had some interest to pay unexpectedly. I had negotiated three months' deferment of interest on a loan, or at least I thought I had, and then I got a threatening demand. I had to pay at once or they'd start proceedings." The desperation he said wasn't there, definitely had been; it still echoed in his voice. "I couldn't have it getting around the golf club, could I?" he demanded. "No one in the family could lend me a large sum in a hurry. Our ordinary bank overdraft is always at maximum. The finance company was inflexible. I knew Malcolm wouldn't give me the money, he has those stupid warped views, but I did think he might guarantee… just for a short while…"

To save the whole pack of cards collapsing, perhaps he might. Malcolm wasn't cruel. He'd lent Edwin money sometimes in the past. Donald, I thought, had stood a good chance.

"But when you'd found where he was, you didn't get in touch with him, did you?"

"No," Donald said. "I didn't relish telling Malcolm our troubles. I didn't want to look a fool, and Helen thought of a different way out."

I looked at her enquiringly.

"Popped my baubles," she said with a brave attempt at lightness. "Took them to London. All my lovely rocks." She held her head high, refusing to cry.

"Pawned them?" I said.

"We'll get them back," she said valiantly, trying to believe it.

"What day did you pop them?"

"Wednesday. Donald took the money in cash to the finance company, and that gives us a three-months' breather."

Wednesday, I thought. The day after someone had failed to kill Malcolm at Newmarket. "When did the finance company start threatening you?"

"The Thursday before," Helen said. "They gave us a week. They were utterly beastly, Donald said."

"Vivien tried to get Malcolm to give us some money," Donald said with resentment, "and he flatly refused." "Well," I said, half smiling, "she called him an evil, wicked, vindictive tyrant, and that's not the best way in the world to persuade Malcolm to be generous. If she'd used honey, she might have succeeded."

Helen said, "You're the only one he'll listen to. I don't care if you get millions more than us. All the others are furious about it, they don't believe it about equal shares in his will, but I don't care. If you could just… I mean…"

"I'll try," I promised, "but the equal shares are true."

It fell on deaf ears. They believed what they believed, the whole lot of them, feeding and reinforcing their fears every time they consulted.

I left Donald and Helen among their antique furniture and behind their shaky facade and trundled along to Quantum to see how things were developing.

Not fast, was the answer. The place was abandoned except for a solitary uniformed policeman sitting in a police car outside what had been the front door. One could see right through the house now. The tarpaulin that had hung from the roof had come down. The policeman was the one who had accompanied me on my tour of peering in through the windows, and I gathered he was pleased to have a visitor to enliven a monotonous stint.