After witnessing the dramatic explosion of the Orca, the ship with his family aboard, Carter Kingsley believes his sister Bea and her godfather Theodore have drowned, alongside his beloved pet saur, Buster the Dwarf Black Tyrant. Bereft and vulnerable, he is taken in by the villainous Viscount and his wife, Anya Stitz.

But his family were saved by the saurs they were travelling with, and are still alive. With their new knowledge that the Viscount is hellbent on fulfilling his plans to create a new species of bio-engineered saurs that can be sold for profit - and for bloodshed - Bea and Theodore must somehow track Carter across Europe without being detected. They must stop the Viscount from achieving his aims ... and release Carter from his seductive influence before it is too late.

Hidden within the closed world of a travelling circus, Bea and Theodore forge friendships with the self-confessed 'freaks' that will allow them to pull off the most daring rescue plan with the help of Buster and the other circus saurs. With danger at every stop of the big top, they must use their combined powers to triumph in the ultimate saur showdown...