Jackie and Jade guide a rich museum patron named Doctor Smith through the African bush, in search of ruins from the legendary Lost City of the Muntabs. They discover that the city still exists, hidden behind a cloak of invisibility. The Chans were captured, and Jackie must survive the Cave of Truth to prove he's pure of heart. As Jade befriends Abila, a young-looking Muntab girl who was actually more than 200 years old, Smith discovers the Muntab's secret of immortality: the Chalice of Life. Smith steals the Chalice, which Jackie and Jade must get back before the Muntabs age and turn to dust.