“It’s a genetic weapon,” she said clearly. “In the Unsettlement, there were volunteer Black Brigade cadres who had their DNA modified to carry it. A gene-level hatred of Harlan family blood, pheromone-triggered. It was cutting-edge technology, out of the Drava research labs. No one was sure if it would work, but the Black Brigades wanted a beyond-the-grave strike if we failed at Millsport. Something that would come back, generation after generation, to haunt the Harlanites. The volunteers, the ones that survived, would pass it on to their children and those children would pass it on to theirs.”

“Nice.”

“It was a war, Kovacs. You think the First Families don’t pass on a ruling-class blueprint to their offspring? You think the same privilege and assumption of superiority isn’t imprinted, generation after generation?”

“Yeah, maybe. But not at a genetic level.”

“Do you know that for a fact? Do you know what goes on in the First Family clone banks? What technologies they’ve accessed and built into themselves? What provision there is for perpetuating the oligarchy?”

I thought of Mari Ado, and everything she’d rejected on her way to Vchira Beach. I never liked the woman much, but she deserved a better class analysis than this.

“Suppose you just tell me what this fucking thing does,” I said flatly.

The woman in Oshima’s sleeve shrugged. “I thought I had. Anyone carrying the modified genes has an inbuilt instinct for violence against Harlan family members. It’s like the genetic fear of snakes you see in monkeys, like that built-in response the bottlebacks have to wingshadow on water. The pheromonal make-up that goes with Harlan blood triggers the urge. After that, it’s just a matter of time and personality—in some cases the carrier will react there and then, go berserk and kill with anything to hand. Different personality types might wait and plan it more carefully. Some may even try to resist the urge, but it’s like sex, like competition traits. The biology will win out in the end.”

“Genetically encoded insurgency.” I nodded to myself. A dreary kind of calm, descending. “Well, I suppose it’s a natural enough extension of the Quellcrist principle. Blow away and hide, come back a lifetime later. If that doesn’t work, co-opt your great grandchildren and they can come back to fight for you several generations down the line. Very committed. How come the Black Brigades never used it?”

“I don’t know.” She tugged morosely at the lapel of the jacket Tres had lent her. “Not many of us had the access codes. And it’d need a few generations before something like that would be worth triggering. Maybe nobody who knew survived that long. From what your friends have been telling me, most of the Brigade cadres were hunted down and exterminated after I … After it ended. Maybe no one was left.”