Shipwrecked on the remote volcanic island of Agrihan, and with one of them severely injured, Lou Benson and Jim and Staci Kirk have to find their way to civilisation. Joined by orphan Ailsa Cudby, who has been living with a local village since her parents died, they set off past the volcano in search of an abandoned U.S. Air Force base. With time running out to get medical attention, the teens once again face danger in order to save one of their own. Will they find help in time?