Pathfinders to Venus is the fourth and final show that begin with Target Luna, Pathfinders in Space, and Pathfinder to Mars.
The show opens with the crew of MR4 returning from their unexpected trip to Mars when they intercept a distress signal from Captain Wilson, a U.S astronaut, and must change course for Venus to attempt a rescue in space.
However, through the space periscope, Brown sees what appears to be a settlement or a city of some sort. Desperate to investigate, Brown edits Wilson’s message and tricks the crew into landing Venus so as they can rescue him.
Landing on Venus, the crew discover, much to Brown’s delight, that the planet is capable is sustaining life and is a vast jungle. Investigating further, the party find Wilson’s rocket-capsule, the US V7, ransacked and ripped apart from the inside by something. Brown gets separated from the others and finds Wilson, who then tricks him into finding his ‘city’.
Henderson, Meadows, Geoff, Rosie and Hamlet find the trail leading into the caves of the volcano and get separated. Whilst separated, Henderson, Geoff and Meadows find cavemen whilst Margret (and Hamlet) finds Wilson, Brown and a Venusian cave-child whom she names ‘Kiki’. Reunited, the group are forced to escape the lava flow and find themselves in a desert.
Keeping to the left and through the desert, the Wedgwood party discover dinosaurs, diamonds anduUranium. When they get nearer Brown’s city, they find it to be nothing but an ancient burial ground for Kiki’s ancestors. As the journey progresses, the party realize that Venus is a living duplicate of Earth, with dinosaurs and prehistoric humans existing parallel to each other.
Finally returning to the jungle, they discover the lava has set the jungle alight in the direction of MR4. Brown, determined that the planet must not be ruined from what they’ve seen, decides to set the rocket to overload. However, Henderson turns the tables on him, just in time to see a Russian rocket land nearby. The pilot, Colonel Korolyov, explains they have extra fuel for MR4, in exchange for Wilson’s secret mission, which was in fact, an experiment in telecommunications.
Preparing to leave, Brown announces he is remaining behind, since Kiki has lost her parents and aware of the responsibilities of hijacking MR4 in the first place and that to him, Venus is an unspoiled paradise.
Taking off, MR4 is given fuel for the return journey in Space. Finally after months away from home, the Wedgwood party plus Wilson finally return to Earth on Buchan Island.