For eighteen months he has lived by one law: a thing that never broadcasts cannot be found.
He has no name anyone will use and no wire in his skull. He hears the machine through a lead that rests against the bone behind his ear, reads the world off a needle that cannot be made to tell him anything untrue, and has stayed alive by making certain, every night, that he was never there at all.
Then, thirty feet under a dead transit interchange, something with a heartbeat moves through the Grid's own bookkeeping.
He was not the last one.
Answering it means becoming findable. It means crossing live water with a child on his shoulder and four strangers behind him, the current weighing the whole way whether they are worth taking. It means waking thirty-five junctions the machine was never built to hear, one stolen cycle at a time. It means trusting a woman who spent four hundred and twelve days inside the architecture deciding who lived, and called it arithmetic so that she could keep doing it.
The machine can find a mouth. It has no way in the world to find an ear.
He built a life on that difference. He is about to spend everything he has left finding out what it costs.