Emily and Alexander visit their cousin Nikos in Crete. He tells them that excavations are being carried out in the palace of Kuossos and that the treasures they find keep disappearing. With their human friend Costas, they set out to solve the mystery. The famous Minotaur comes back to life and scares everyone terribly. But the mice are not dissuaded from finding out the secret and soon find out that Notail Nogoodnik has his fingers in the pie.