Ten-year-old twins Jemima and Joe Lancelot continue the search for their missing parents who are trapped somewhere in the past. Together with best friend Charlie, and their talking cat Max, they are transported back in time to ancient Crete and the Palace of Knossos, where the fearsome Minotaur lurks in its labyrinth, feeding on human flesh. Can they help Prince Theseus of Athens destroy the terrifying monster before it devours them all? And will the children survive the storm that threatens to wreck their ship as they attempt to flee the island?