Wayne creates a skin lotion to make people become great swimmers like fish in the water. Amy takes some of it to a pool party that she is invited to. When Amy uses the lotion, she becomes the life of the pool party so the girl who the party is being held for tries it as well. However, things go terribly wrong (as usual) when the girls find the lotion has turned them into "mermaids". They'll end up completely turning into fish unless Wayne can create an antidote. However, things get even worse when the desperate and greedy owner of the pool kidnaps the girls to use them as a money-making attraction.