Tory Brennan , the great - niece of Dr. Tempe Brennan , and the Virals return for a third thrilling adventure on Loggerhead Island . The Virals are put to the ultimate test when they find a geocache containing an ornate puzzle box . Shelton decodes the cipher inside, only to find more tantalizing clues left by “The Gamemaster ”. A second , greater geocache is within reach – if the Virals are up to the challenge . But the hunt takes a dark turn when Tory locates the other box – a fake bomb, along with a sinister proposal from The Gamemaster . Now, the real game has begun : another bomb is out there – a real one – and the clock is ticking.
