“Badly enough to take that risk?” Kim asked, and then, more slowly, “Yes, perhaps. Because he didn’t get the money, and then someone stuck an ice-pick in his ear. Post hoc ergo propter hoc?”

“Couldn’t say.”

“I’m wondering if we’re on to something. Let’s assume Yoxall is telling the truth. That suggests Fairfax was sufficiently in need of money to risk his standing at the Symposium on a very shaky bit of extortion. He got killed subsequent to his failed fundraising efforts—by whoever he owed money to? Or by another victim, because we can surely assume there were more? Oh, this is marvellous. If we’re looking at not just other blackmailees, but also people to whom Fairfax owed money, if we can argue that Fairfax had other enemies, we have the beginnings of a case. Threads of reasonable doubt for my father’s lawyers to weave into whole cloth, if you’ll forgive the overextended metaphor.”

Will had other concerns than metaphors. “Hold on. If you can do the reasonable doubt thing, won’t Chingford get off?”

“If the prosecution can’t persuade the jury of their case, the verdict should be not guilty. That’s the law.”

“There’s a difference between not guilty and innocent! If a man did it but the police can’t prove it—”

“Then he doesn’t hang. That’s how it ought to be. Certainly better than the alternative.”

Will gave him a look. “And he gets away with murder.”

“Only if he did it. I don’t know if Chingford did it and nor do you.”

“Oh, come on.”

Kim held one palm up. “Yes, all right. But the accused is still entitled to a defence, isn’t he? That’s all I’m trying to do here: give him a defence. If I can’t scrape something plausible together, the law will take its course.”

“Suppose.” Will scrubbed a hand through his hair. “Why are you doing this?”

“Doing what?”

“Don’t do that, Kim. You know what I asked.”

“Sorry. Yes.” Kim exhaled. “I wish I had a good answer. I don’t want to take his place, needless to say. And I don’t want another dead brother. If there is something I can do to prevent that outcome, I think I have to do it.”

“For who? Your father?”

“He doesn’t want my help. Let’s say, for myself.”

“And does this make up for Henry?”

“Henry is dead,” Kim said. “There’s no making up for that. But my father would prefer Chingford to live, and if I could achieve that...”

He tailed off. Will would have liked to press on what the if led to. He’ll forgive me? I’ll forgive myself?

He didn’t press, because he wasn’t sure Kim had an answer. Instead, he asked, “And you’re all right with this? Yes, blackmailers have it coming, but that was a sodding cold killing.”