Louie, was abandoned at Chipchase's Travelling Circus as a baby and dreams of becoming a 'Showstopper'. She secretly practises the tightrope and dreams of being the Girl Who Walked on Air. Mr Chipchase reluctantly lets Louie perform. She is a sensation, and gets an offer from the sinister, opposition, Mr Wellbeloved to perform... over Niagara Falls. But nothing is quite as it seems and soon Louie's bravery is tested not just on the highwire but in confronting her past and the shady characters in the world of the circus.