Rebecca Connolly was a gorgeous woman. According to the press reports I’d read, she was forty-four, but she looked twenty years younger. Gene therapy might be impossible here, but anyone who could afford it could have plastic surgery. Her hair was copper-colored, and her eyes an unnatural violet. “Hello, Detective Korsakov,” she said. “My husband told me you were likely to stop by.” She shook her head. “Poor Skye. Such a darling man.”

I tilted my head. She was the first of Skye’s relations to actually say something nice about him as a person — which, after all, could just be a clumsy attempt to deflect suspicion from her. “You knew Skye well?”

“No — to be honest, no. He and Rodger weren’t that close. Funny thing, that. Skye used to come by the house frequently when we first got married — he was Rodger’s best man, did he tell you that? But when Glen was born, well, he stopped coming around as much. I dunno — maybe he didn’t like kids; he never had any of his own. Anyway, he really hasn’t been a big part of our lives for, oh, eighteen years now.”

“But Rodger’s fingerprints were accepted by Skye’s lock.”

“Oh, yes. Rodger owns the unit Skye has his current offices in.”

“I hate to ask you this, but -”

“I’m on the Board of Directors of TenthGen Computing, Detective. We were having a shareholders’ meeting this morning. Something like eight hundred people saw me there.”

I asked more questions, but didn’t get any closer to identifying Rodger Hissock’s motive. And so I decided to cheat — as I said, sometimes I do wonder if I’m in the right kind of job. “Thanks for your help, Ms. Connolly. I don’t want to take up any more of your time, but can I use your bathroom before I go?”

She smiled. “Of course. There’s one down the hall, and one upstairs.”

The upstairs one sounded more promising for my purposes. I went up to it, and the door closed behind me. I really did need to go, but first I pulled out my forensic scanner and started looking for specimens. Razors and combs were excellent places to find DNA samples; so were towels, if the user rubbed vigorously enough. Best of all, though, were toothbrushes. I scanned everything, but something was amiss. According to the scanner, there was DNA present from one woman — the XX chromosome pair made the gender clear. And there was DNA from one man. But three males lived in this house: father Rodger, elder son Glen, and younger son Billy.

Perhaps this bathroom was used only by the parents, in which case I’d blown it — I’d hardly get a chance to check out the other bathroom. But no — there were four sets of towels, four toothbrushes, and there, on the edge of the tub, a toy aquashuttle … precisely the kind an eight-year-old boy would play with.

Curious. Four people obviously used this john, but only two had left any genetic traces. And that made no sense — I mean, sure, I hardly ever washed when I was eight like Billy, but no one can use a washroom day in and day out without leaving some DNA behind.

I relieved myself, the toilet autoflushed, and I went downstairs, thanked Ms. Connolly again, and left.

Like I said, I was cheating — making me wonder again whether I really was cut out for a career in law enforcement. Even though it was a violation of civil rights, I took the male DNA sample I’d found in the Hissock-Connolly bathroom to Dana Rundstedt, who read its sooth for me.

I was amazed by the results. If I hadn’t cheated, I might never have figured it out — it was a damn-near perfect crime.

But it all fit, after seeing what was in the male DNA.

The fact that of the surviving Hissocks, only Rodger apparently had free access to Skye’s inner office.

The fact that Rodger’s blaster was the murder weapon.

The fact that there were apparently only two people using the bathroom.

The fact that Skye hated confrontation.

The fact that the Hissock-Connolly family had a lot of money they wanted to pass on to the next generation.

The fact that young Glen looked just like his dad, but was subdued and reserved.

The fact that Glen had gone to a different soothsayer.

The fact that Rodger’s taste in receptionists was … unusual.

The pieces all fit — that part of my sooth, at least, must have been read correctly; I was good at puzzling things out. But I was still amazed by how elegant it was.

Ray Chen would sort out the legalities; he was an expert at that kind of thing. He’d find a way to smooth over my unauthorized soothsaying before we brought this to trial.

I got in a cab and headed off to Wheel Three to confront the killer.

“Hold it right there,” I said, coming down the long, gently curving corridor at Francis Crick. “You’re under arrest.”

Glen Hissock stopped dead in his tracks. “What for?”

I looked around, then drew Glen into an empty classroom. “For the murder of your uncle, Skye Hissock. Or should I say, for the murder of your brother? The semantics are a bit tricky.”

“I don’t know what you’re talking about,” said Glen, in that subdued, nervous voice of his.

I shook my head. Soothsayer Skye had deserved punishment, and his brother Rodger was guilty of a heinous crime — in fact, a crime Mendelian society considered every bit as bad as murder. But I couldn’t let Glen get away with it. “I’m sorry for what happened to you,” I said. The mental scars no doubt explained his sullen, withdrawn manner.

He glared at me. “Like that makes it better.”

“When did it start?”

He was quiet for a time, then gave a little shrug, as if realizing there was no point in pretending any longer. “When I was twelve — as soon as I entered puberty. Not every night, you understand. But often enough.” He paused, then: “How’d you figure it out?”

I decided to tell him the truth. “There are only two different sets of DNA in your house — one female, as you’d expect, and just one male.”

Glen said nothing.

“I had the male DNA read. I was looking for a trait that might have provided a motive for your father. You know what I found.”

Glen was still silent.

“When your dad’s sooth was read just after birth, maybe his parents were told that he was sterile. Certainly the proof is there, in his DNA: an inability to produce viable sperm.” I paused, remembering the details Rundstedt had explained to me. “But the soothsayer back then couldn’t have known the effect of having the variant form of gene ABL-419d, with over a hundred T-A-T repeats. That variation’s function hadn’t been identified that long ago. But it was known by the time Rodger turned eighteen, by the time he went to see his big brother Skye, by the time Skye gave him his adult soothsaying.” I paused. “But Uncle Skye hated confrontation, didn’t he?”

Glen was motionless, a statue.

“And so Skye lied to your dad. Oh, he told him about his sterility, all right, but he figured there was no point in getting into an argument about what that variant gene meant.”

Glen looked at the ground. When at last he did speak, his voice was bitter. “I had thought Dad knew. I confronted him — Christ sakes, Dad, if you knew you had a gene for incestuous pedophilia, why the hell didn’t you seek counseling? Why the hell did you have kids?”

“But your father didn’t know, did he?”

Glen shook his head. “That bastard Uncle Skye hadn’t told him.”

“In fairness,” I said, “Skye probably figured that since your father couldn’t have kids, the problem would never come up. But your dad made a lot of money, and wanted it to pass to an heir. And since he couldn’t have an heir the normal way…”

Glen’s voice was full of disgust. “Since he couldn’t have an heir the normal way, he had one made.”

I looked the boy up and down. I’d never met a clone before. Glen really was the spitting image of the old man — a chip off the old block. But like any dynasty, the Hissock-Connolly clan wanted not just an heir, but an heir and a spare. Little Billy, ten years younger than Glen, was likewise an exact genetic duplicate of Rodger Hissock, produced from Rodger’s DNA placed into one of Rebecca’s eggs. All three Hissock males had indeed left DNA in that bathroom — exactly identical DNA.