Jake and his younger brother Tommy are visiting family at a beach house on the coast. Having already lost a race to his cousin Lexie, Jake can't resist a second chance at victory when she challenges him again. Only this time it's a boat race-to the legendary Smuggler's Cave and back. The ocean is deep and choppy, and the boat is harder to control than Jake thought it would be. When he and Tommy reach Smuggler's Cave, the unthinkable happens. The boat capsizes, and they are swept into the cave. Lexie comes to their rescue, but the rising tide prevents them from escaping, and the three of them soon realize they are trapped.