Silicon Valley: home of online start-ups, couture coffee, sexual meditation, and the future. In its midst, Neill Bassett is helping to build the world's first artificial intelligence - a computer that talks, thinks, lies and, if all goes to plan, feels bad about it too. But when the experiment swerves in an unexpected direction, Neill is forced to confront a few buried feelings of his own - for his ex-wife, for his dead father, for his twenty-first-century life and for a very twenty-first-century woman called Rachel, who might just hold the answer to it all . . .