It's migration time and as a mother gull dives into the water to catch a herring she's caught in an oil slick! Thinking of the egg she is about to lay she manages to extract herself and fly to the nearest port. Exhausted, she lands on a balcony where Zorba the cat is sunning himself. Zorba wants to get help, but the gull knows it's too late and she extracts three promises from him: 1) That he won't eat the egg, 2) that he'll take care of the chick until it hatches, and 3) that he'll teach it to fly. The first two are hard enough, but the third one is surely impossible. Isn't it?
