King of the Rocket Men Part7 Molten Menace

Professor Millard (James Craven) has finished the construction of a new device he calls "the decimator," a thromium wave super-weapon capable of melting solid rock and steel! Learning the location of Millard's secret cave laboratory, Dr. Vulcan orders Dirken (Don Haggerty) to kidnap Millard and steal the decimator. Jeff King races to the cave as Rocket Man, but what good is the power of flight when trapped underground in a torrent of molten lava! (1949 - Republic Pictures)