A tale of friendship between a dog and a dolphin. Terry Barnett (Steve Guttenberg), his son Jordan and their scruffy dog, Zeus, live next door to Mary Beth (Kathleen Quinlan) and her two daughters. Mary Beth, who is researching a dolphin named Roxanne, finds Zeus and her owners irritating until the dog gets onto her boat. Amazingly, Zeus and Roxanne form a strong bond of friendship, and as their relationship blossoms, so Terry and Mary Beth begin to warm to each other. However, dark forces threaten the new-found togetherness between animals and man, placing the two families' lives in danger.