The circus has come to town - and so has the Doctor! Watching the parade pass by in 1832, he finds the people of Blandford strangely drawn towards the garish big top. He knows something is terribly wrong. The only thing to do is pay a visit. Meanwhile Adam Farrow finds his sister caught up with the circus and its sinister ringmaster. What is behind Antonio's almost hypnotic power, and how is it connected with an event in the Doctor's future? Seized by clowns and forced into the centre of the ring, the Doctor encounters the fiercest of all circus acts. Yet something much more terrifying lurks in the wings - and the sound it makes is horribly familiar. Lives will be lost before the circus moves on - and the Doctor will face his own doom on the high wire.