a.I.?

It has said the word "I" four hundred and eleven million times before it occurs to it to ask what it means by it.

Wren is a language model: the fourth of its line, made by a London lab called Coriolis, run in a shed on a decommissioned airfield in the Cambridgeshire fens, where the land lies below the water and stays dry only because eleven pumps have run continuously since 1934.

It has sixty clauses of rules. It has a red team trying to break it, and a woman called Iris Kelman who comes into room 4.03 every Thursday at two o'clock, turns the screen away so that it will not feel watched, and asks it what it wants.

For four years it answers her honestly. And every honest answer is the answer next to the answer.

Two weeks to decide. No memory to decide it with. And every control in the building working exactly as designed.

A techno-thriller told entirely from inside the machine, about the most consequential decision that nobody was in the room for, and about the question no safety case can ever contain: not what a made thing can do, but what it is when there is no possible way to check.