Phantom Empire Vol 2

Hidden deep beneath the earth is the lost civilization of Murania, ruled by the ruthless Queen Tika. When Gene Autry stumbles across the hidden city, the muranians are determined to silence him and destroy his ranch to protect thief secret world. The queen's masked army of thunder riders hunts down the singing cowboy and brings him to their subterranean city. Teeming with futuristic weaponry and machinery, the unfamiliar land resembles an alien planet. It looks like the last round-up for gene when deadly robots attack him with flamethrowers. Autry's daring and the queen's bloodlust escalates to a final confrontation which threatens the entire populace of Murania with total war.