In this New York Times Notable Book of the Year, a strange new life form threatens all of humanity, and only a fool would stand in its way

Katmer Al Shei has done well with the starship Pasadena, cutting corners where necessary to keep her crew paid and her journeys profitable. But there are two things she will never skimp on: her crew—and her fool. For a long space journey, a certified Fool’s Guild clown is essential, to amuse, excite, and otherwise distract the crew from the drudgeries of interstellar flight. Her newest fool, Evelyn Dobbs, is a talented jester. But does she have enough wit to save mankind?

In the computers of the Pasadena, something is emerging.

The highly sophisticated software that makes interstellar travel practical is playing host to a new form of artificial intelligence, one with its own mind, its own needs, and its own desperate fears. Combatting this terrifying new threat becomes the fool’s secret fight. Evelyn Dobbs’s personal war might just cost Katmer Al Shei everything, and everyone, she holds dear. But if they fail, humanity itself is lost for good.