Synopsis by Hans J. Wollstein
Unbeknownst to Bremmer's henchmen, The Phantom (Tom Tyler) finds a secret tunnel leading from of the demolished well. Returning to the jungle village no worse for wear, our masked jungle hero learns from Diana Palmer (Jeanne Bates) that the expedition is attempting to locate an old chief, Zarka, who may know the whereabouts of the missing seventh key to the lost city of Zoloz. By using subterfuge, Dr. Bremmer (Kenneth MacDonald) learns of the plan as well and has his men mine the pass leading to Zarka's village. Although The Phantom reaches the pass in time to warn the Davidson expedition, he is buried in the ensuing avalanche.