Sent to spend the summer with their uncle on a remote island, young brothers Andy and Mark learn that their eccentric grandfather once owned the island, but vanished without a trace…taking with him the secret to a vast fortune. Delving into the mysterious past of the island, the brothers discover that their grandfather designed a complex treasure hunt, a hunt that could lead to unimaginable wealth and heal their broken family – if they can find it in time. Sinister forces also search for the money and will stop at nothing to keep the boys from their quest. As the adventure unfolds, the boys learn that the bonds of family are the most valuable riches of all, and that some family secrets can't stay buried forever.