The jungle is mystified by the reclusive new owner of the peaceful and picturesque Green Valley. The valley has been shut off, a large house has been erected, and rumour has it that a large monster resides inside. The mystery deepens further when bandits dressed exactly as the Green Valley guards raid and rob a jungle caravan.

After the jungle folks are forcibly driven from the premises during an attempt to storm the large house, the tribal chiefs turn to the Phantom for help. Ignoring advice to the contrary, the Phantom decides to confront the monster head-on and learn the baffling truth about the strange goings-on...