In order to continue her research on whales, Dianne Bates is assigned to ORCA. She arrives there to do the research with Dr Winston Seth. Her two sons, Jason and Brett, have to go, too. Although younger brother Brett finds the underwater research station exciting, Jason is not happy about the change in scenery. Jason is given the job of tagging a whale, but fails to do so when he sees a girl in the ocean. His mother doesn't believe his story and feels he sabotages it on purpose.