Captain Jim Wedderburn has looks, style and courage by the bucketful. He's adored by women, respected by men and feared by his enemies. He's the man to find out who has twisted London into this strange new world, and he knows it. But in Dream London the city changes a little every night and the people change a little every day. The towers are growing taller, the parks have hidden themselves away and the streets form themselves into strange new patterns. There are people sailing in from new lands down the river, new criminals emerging in the East End and a path spiralling down to another world. Everyone is changing, no one is who they seem to be.

Anna Sinfield marched into the parks, when Angel Tower burned and Dream London fell. She marched to free the city, to end the madness, to find her mother and father. The day was won,. but her parents—and thousands like them—are still missing, lost to the Dream World. And now she has a chance to get them back. A man with gemlike eyes has walked into her life, wearing a bespoke suit and bearing a terrible scroll. Mr Twelvetrees claims to know where the missing Londoners are; but to find them, Anna has to give up a life she's started to rebuild and go into the Dream World itself. Into another Paris, where history has been repeating itself for two hundred years. Vive La Révolution!