We meet Dr. Mata in one of her townhouses by SF State. The walls are pure white and there is no furniture. Dr. Mata is Japanese-American and tiny, barely coming up to my shoulder, and I’m not the tallest of women. She’s also one of the few people in San Francisco who has let herself age, at least a little. There’s the barest hint of wrinkles around her eyes and at either side of her mouth. It’s refreshing to see a face that looks lived in, evidence of countless smiles reflected on her skin. I estimate she’s about forty-five. She has dark hair cut in a bob to the corner of her jaw, and a face that’s always on the verge of grinning.

“Can’t keep away from me, can you, darling?” she says, dimpling at Detective Nazarin.

“My heart beats only for you, Kim,” he responds, deadpan.

She rolls her eyes. I’m amused by their exchange. Dr. Mata is open and friendly, and Detective Nazarin seems more at ease around her. With her easy manner and the way she slouches against the wall, she doesn’t strike me as one of the most prominent biohackers in the world and worth a few million credits or more.

“What’s it to be this time, sweets?” she asks. Her gaze flicks to me, assessing me from head to toe, before she focuses on the detective again. “Better not be too trying. I have back-to-back meetings all afternoon and if you tire me out, I’ll nap through them.”

“Identity switch,” he says. “This is a sensitive matter. I saw you returned the confidentiality agreement to HQ.”

“I’m hurt you don’t trust me,” she pouts. “When have I ever let you down?”

“Never. I trust you implicitly.”

In contrast to their earlier banter, he’s serious here, and she feeds off it. Dr. Mata looks at me again. “OK. What’s up?”

“Kim, this is Taema Collins. Her sister, Tila Collins, has been accused of murder.”

Dr. Mata’s eyes widen. “Civilian?”

“Not exactly,” he replies. “Tila Collins is implicated with the Ratel. Last night she was caught and accused. You know what I’ve been doing with myself the last few years.”

“Yeah, being an idiot and playing with fire. I’ve told you time and time again you need to get out of that game.”

“You speak sense as always, but I can’t. Anyway, I never would have been able to do what I’ve done without you.”

She blows him an air kiss. “Damn right. So you’re being taken into protective custody or something?” Dr. Mata asks, addressing me for the first time. “Need a new identity to lie low?”

I shake my head. “Not exactly. Tila and I—we’re identical twins, you see.”