Page 119 of The Chain

The Karush-Kuhn-Tucker conditions are optimal. The information is there if you know where and how to look. All those hints, all those personal ads, all those confessions. Every new person introduced to The Chain adds a geometric level of instability. The thing has been teetering on the verge of collapse for a long time. It’s just figuring out a way to harness the data points into a shape.

He sips coffee and reads an interesting paper by Maria Schuld, Ilya Sinayskiy, and Francesco Petruccione on prediction by linear regression on a quantum computer. Their algorithm is fascinating.

But it is, he knows, a distraction, something for future analysis.

Amazon’s Alexa is playingPhysical Graffitifor the third time tonight. He stops to listen to the opening riff of “Trampled Under Foot.”

He looks at the photograph of himself, his wife, and his daughter in front of MoMA, in New York. His wife’s favorite place in all the world. His wife and daughter are grinning while he looks pained.

He shakes his head and fights the tears and looks at the bullet points on the screen that he will have to condense for his Chain notebook.

Things are OK. While he hasn’t completely tested the app, he thinks itshouldwork. And it should work only for Rachel.

He reorders the list on his screen. These are the things he is fairly certain of now:

At least two individuals. Two different signatures and modes of operation. Family members. Siblings?

Boston-based

Not organized crime

Some kind of law enforcement background

“Trampled Under Foot” ends and “Kashmir” begins.

The woman has been watching him for ninety seconds now. Her heart rate is through the roof.

Her instructions are clear: kill Erik, retrieve his notebook.

She knows why The Chain picked her—because of her two previous breaking-and-entering convictions. They think she’s some kind of expert. She’s not. Those were teenage indiscretions. She’s a respectable fifth-grade teacher now. She got lucky that Erik’s back door was such an old lock. There was barely any skill required.

She got lucky.

Erik got unlucky.

She has in fact killed before. A dog on the road out on Cape Cod. She’d hit it, and she had to put it out of its misery with a snow shovel.

Maybe that’s what she’s doing to Erik.

His wife is dead. His daughter is in an asylum.

Yes,she thinks and aims the gun at his back.

62

Pete’s alarm goes off at five o’clock. He kills it before it wakes Rachel and quickly rolls out of bed.

His skin and eyes and internal organs are craving the fix. It has been a full day now. One of his longest fasts yet. He is trying a technique called stretching that some guys in the program have recommended. You stretch out the time between hits as long as you can—you go a full day, then a day and a half, and then two days. He looks at the clock. Twenty-five hours and five minutes. Getting up there. Getting close to his record. He feels OK. So far.

He makes coffee, does a few pushups, and goes into the bathroom and locks the door. What would happen if he boils half as much as normal? Can he wean himself off that way? Could that work? Half is crazy. Two-thirds, maybe.

He measures out two-thirds of his normal dose, boils it up on a spoon, sucks it into the syringe, injects himself with the good stuff.

He lies down on the sofa and the beautiful dreams take hold of him for an hour.

He wakes up again.

He could have gone longer. He’s feeling fine.