Stan Potts is just an ordinary boy, but when all the jobs in Fish Quay disappear, his uncle develops an extraordinary fascination with canning fish. Suddenly their home is filled with clanging machinery, the stench of mackerel, and an uncle so driven by the business that he would even can Stan's beloved goldfish! But Stan is destined to follow Pancho Perlli, the blue-caped madman who swims with piranhas and as he delves into the waters, he finally discovers who he really can be.