Old Time Radio Sci-Fi, Horror Etc...

Doc deduces that Whitaker and McLean had been 'conditioned', allowing them to be controlled, as well as breathe in the Martian atmosphere. Mitch becomes separated from the others, and meets a man who claims to be a dingo hunter in Australia.

McLean, pretending to be Mitch, enters the land truck and tries to overpower Lemmy, but Lemmy wins the fight. Meanwhile, Mitch, lost in the desert and now able to breathe the Martian atmosphere, comes across a house inhabited by a man and woman who claim to be sheep farmers living in Australia in 1939.

Jet, Doc and Lemmy discover the same house, and find Mitch inside it. But Mitch is now 'conditioned' to believe he's in Australia, and doesn't recognise the others. He refuses to rejoin them, and attacks Jet.

A 'flying doctor' arrives in a sphere, and manages to capture Doc and Lemmy. He tries to 'condition' them using the soporific noise, but they manage to resist. Meanwhile, Jet escapes back to the land trucks.

The sphere arrives at Lacus Solis (the Martian capital), and the flying doctor reveals the Martian plan to invade the Earth in 1986. Frank, flying in Freighter 1, hears the soporific noise and his freighter crashes.

Doc and Lemmy overpower the flying doctor, and escape in the sphere with Mitch, who recovers from his 'conditioning' but can only remember being two weeks away from reaching Mars. Jet is contacted by Webster, a man trying to return to Earth, and learns more about the Martians..

The Discovery crew are fully reunited at last, and thanks to advice from Webster, Mitch completes his recovery. Jet, Lemmy and Webster try to rescue Frank, but they fail, and Webster is injured and dies. The crew return to Discovery at Polar Base and take off for home, escaping a pursuing fleet of spheres. Their news of the upcoming Martian invasion is passed to Earth, causing a great commotion.

The rocket "Luna" sets off for the Moon with Jet, Doc, Mitch and Lemmy aboard. Radio contact with Earth is lost. Lemmy hears odd 'music' on the radio, before contact is resumed, and a tiny meteor hits Luna. No damage is sustained, but Lemmy hears the strange music again outside the ship and panics.

Luna is turned round for the Moon landing, and Lemmy hears the 'music' again during the final approach. The crew narrate their first moonwalk by radio to Earth. While exploring a crater, Jet unaccountably vanishes from sight.

Jet has visions of the past and the future, Lemmy is disturbed by the 'music' again, and Doc sees a strange dome over a crater and writes an odd diary entry without realising. The last week on the moon passes without incident, but as the crew prepare to leave for home, the ship loses all power.