Twin sisters Keziah and Tilly Lovell are identical in every way, except that Tilly hasn't grown a single inch since she was five. Coerced into promoting their father's quack elixir as they tour the country fairgrounds, at the age of fifteen the girls are sold to a mysterious Italian known as ‘Captain’.

Theo is an orphan, raised by his grandfather, Lord Seabrook, a man who has a dark interest in anatomical freaks and other curiosities … particularly the human kind. Resenting his grandson for his mother’s death in childbirth, when Seabrook remarries and a new heir is produced, Theo is forced to leave home without a penny to his name.

Theo finds employment in Dr Summerwell’s Museum of Anatomy in London, and here he meets Captain and his theatrical ‘family’ of performers, freaks and outcasts.

But it is Theo’s fascination with Tilly and Keziah that will lead all of them into a web of deceits, exposing the darkest secrets and threatening everything they know…