Book 8 in the Rivers of London series, from Sunday Times Number One bestselling author Ben Aaronovitch.

Peter Grant is facing fatherhood, and an uncertain future, with equal amounts of panic and enthusiasm. Leaving his old police life behind, he takes a job with Silicon Valley tech genius Terrence Skinner’s new London start up: the Serious Cybernetics Corporation.

Drawn into the orbit of Old Street’s famous ‘silicon roundabout’, Peter must learn how to blend in with people who are both civilians and geekier than he is. Compared to his last job, Peter thinks it should be a doddle. But magic is not finished with the Met’s first trainee wizard in fifty years.

Because a secret is hiding somewhere in the building. A technology that stretches back to Ada Lovelace and Charles Babbage, and forward to the future of artificial intelligence. A secret that is just as magical as it technological – and twice as dangerous…