Blindsight

"We don't." And the others are hacks. "Thing about game theory is, it assumes rational self-interest among the players. And people just aren't rational."

"It used to assume that," I allowed. "These days they factor in the social neurology."

"Human social neurology." She bit a corner off her brick, spoke around a mouthful of semolina. "That's what game theory's good for. Rational players, or human ones. And let me take a wild stab here and wonder if either of those is gonna apply to that." She waved her hand at some archetypal alien lurking past the bulkhead.

"It's got its limitations," I admitted. "I guess you use the tools you can lay your hands on."

Sascha snorted. "So if you couldn't get your hands on a proper set of blueprints, you'd base your dream home on a book of dirty limericks."

"Maybe not." And then, a bit defensive in spite of myself, I added, "I've found it useful, though. In areas you might not expect it to be."

"Yeah? Name one."

"Birthdays," I said, and immediately wished I hadn't.

Sascha stopped chewing. Something behind her eyes flickered, almost strobed, as if her other selves were pricking up their ears.

"Go on," she said, and I could feel the whole Gang listening in.

"It's nothing, really. Just an example."

"So. Tell us." Sascha cocked James' head at me.

I shrugged. No point making a big thing out of it. "Well, according to game theory, you should never tell anyone when your birthday is."

"I don't follow."

"It's a lose-lose proposition. There's no winning strategy."

"What do you mean, strategy? It's a birthday."

Chelsea had said exactly the same thing when I'd tried to explain it to her. Look, I'd said, say you tell everyone when it is and nothing happens. It's kind of a slap in the face.

Or suppose they throw you a party, Chelsea had replied.

Then you don't know whether they're doing it sincerely, or if your earlier interaction just guilted them into observing an occasion they'd rather have ignored. But if you don'ttell anyone, and nobody commemorates the event, there's no reason to feel badly because after all, nobody knew. And if someone doesbuy you a drink then you know it's sincere because nobody would go to all the trouble of finding out when your birthday is— and then celebrating it—if they didn't honestly like you.

Of course, the Gang was more up to speed on such things. I didn't have to explain it verbally: I could just grab a piece of ConSensus and plot out the payoff matrix, Tell/Don't Tell along the columns, Celebrated/Not Celebrated along the rows, the unassailable black-and-white logic of cost and benefit in the squares themselves. The math was irrefutable: the one winning strategy was concealment. Only fools revealed their birthdays.

Sascha looked at me. "You ever show this to anyone else?"

"Sure. My girlfriend."

Her eyebrows lifted. "You had a girlfriend? A real one?"

I nodded. "Once."

"I mean after you showed this to her."

"Well, yes."

"Uh huh." Her eyes wandered back to the payoff matrix. "Just curious, Siri. How did she react?"

"She didn't, really. Not at first. Then—well, she laughed."

"Better woman than me." Sascha shook her head. "I'd have dumped you on the spot."

* * *

My nightly constitutional up the spine: glorious dreamy flight along a single degree of freedom. I sailed through hatches and corridors, threw my arms wide and spun in the gentle cyclonic breezes of the drum. Bates ran circles around me, bouncing her ball against bins and bulkheads, stretching to field each curving rebound in the torqued pseudograv. The toy ricocheted off a stairwell and out of reach as I passed; the major's curses followed me through the needle's eye from crypt to bridge.

I braked just short of the dome, stopped by the sound of quiet voices from ahead.

"Of course they're beautiful," Szpindel murmured. "They're stars."

"And I'm guessing I'm not your first choice to share the view," James said.

"You're a close second. But I've got a date with Meesh."

"She never mentioned it."

"She doesn't tell you everything. Ask her."

"Hey, this body's taking its antilibs. Even if yours isn't."

"Mind out of the gutter, Suze. Eros is only one kind of love, eh? Ancient Greeks recognized four."

"Riiight." Definitely not Susan, not any more. "Figures you'd take your lead from a bunch of sodomites."