When Thomas' younger sister, Tia, gets kidnapped during a trip to Venice, no one believes he has discovered a clue as to her whereabouts. Tia is blind and Thomas is there to help her. So it's up to him to race across Venice, navigating canals, carnival parades and masked balls, to try and rescue her from her captors.

When Tia wins an art prize trip to Venice her older brother, Thomas, is delighted to go with her as family support because Tia is blind, even though his clumsiness causes its own issues.

But then Tia disappears and Thomas is sure she has been kidnapped. With no one to believe him, Thomas sets out alone at night to find his sister through the carnival-filled streets and dark canals of the floating city, where he uncovers a hair-raising conspiracy.