Steve Humboldt, an old lifeguard buddy of Mitch and Craig, shows up with his son unexpectedly. But he fails to mention he's on the run from a private investigator hired by his ex-wife to find their son, who Steve recently lost in a custody battle. When Steve's son wanders away with another boy on the beach, an all-out search ensues. The two boys find themselves trapped in a storm drain that is quickly flooding with the high tide. Mitch and Craig must rescue the boys before they're engulfed by the menacing waters.