Life has passed peacefully in the prosperous Greek city of Yolcos since Jason brought home the Golden Fleece 80 years ago. But when the locals erect a statue in honor of Zeus the King of the Gods, his brother Poseidon becomes mad with jealousy. He then issues an ultimatum to the people of Yolcos: build him an even more spectacular statue within seven days, otherwise a huge wave will fall on the city. 

To accomplish this quest, Pattie, a clever young mouse, Sam, the timorous cat who adopted her and Chickos, the wacky seagull, board the mythical ship of Jason and his Argonauts. But this crew of former heroes is somewhat aging and the little band of animals will have to face the most formidable mythological creatures in their place and overcome all the dangers!