JOURNEY... ...with three world-renowned BASE jumpers as they travel 10,000 miles by airplane, river boat and 4x4 truck... TO... ...confront the mist and mystery of an old cave, an ancient culture, and their own demons at... THE CENTER... ...of their dangerous mission: Tian Keng, the Heavenly Pit. Millions of years old, half a mile deep, waiting for eons to test the endurance, skill and courage of the men who dare to parachute into her heart.