Flash, Thun, Prince Barin & Vultan form an alliance as Dr. Zarkov warns them of the impending destruction to Earth from Mongo's close orbit. The heroes find themselves in Arboria fighting the Metal Men above ground and the mysterious Molemen below ground. They are able to overpower the Molemen and commandeer a large Mole Machine in an effort to gain entrance to Mingo City. It's a race against time as Flash must prevent Ming the Merciless from marrying Dale Arden and save the planet Earth!
