When four young divers discover a legendary shipwreck rumored to contain millions in gold at the bottom of the sea, they believe their dream of buried treasure has come true. But nearby on the ocean floor, a sunken plane full of illegal cargo threatens their find. The friends make a pact to keep quiet about both discoveries so they can excavate the shipwreck before a rival treasure hunter uncovers their secret and beats them to the gold. But their plan goes awry when they realize dangerous smugglers are already closing in on the missing plane, and one of the friends makes a fatal decision that quickly turns the treasure hunters into the hunted.