Jon Dark is a helicopter pilot for the International Red Cross, flying numerous rescue missions...until the day his helicopter crashes in the Cambodian jungles. Cut off from American troops, he searches for a way out, only to find a lost city and the gateway to another world. Stepping through the portal, he arrives on Callistoa savage, hostile world terrorized by insect-men. Here Jon finds not only chilling dangers awaiting him, but also the love of a beautiful princess.