Aired: 3/5/1961
While returning to Earth from a hazardous journey to Mars, the British rocket crew hear a mysterious distress call from the vicinity of Venus.
Aired: 3/12/1961
In answer to a distress call from a stranded astronaut; MR4 has diverted to Venus. By a trick, the rocket's univited guest Harcourt Brown has made pilot Henderson decide to land on the unknown world beneath the carbon cloud.
Aired: 3/19/1961
The crew of the British rocket MR4 have landed on Venus to rescue the stranded American astronaut. But he has vanished and his rocked has been ransacked.
Aired: 3/26/1961
The British rescue party on Venus have found the American's ransacked rocket. Evidence of life is soon confirmed.
Aired: 4/2/1961
Harcourt Brown has persuaded the American astronaut, Wilson to go with hims in search of a Venusian civilisation. The British party in pursuit suddenly find themselves trapped in a cave by a huge primitive man.
Aired: 4/9/1961
The British space explorers, searching inside a Venusian volcano for Captain Wilson, are hunted down by a primitive species of men. Making their escape, they are trapped by roof falls and molten lava as the volcano erupts.
Aired: 4/16/1961
Cut off from their rocket by an active volcano, the astronauts start the long trek across the Venusian desert - and are attacked by pterodactyls. But these pre-historic flying reptiles are only a foretase of what is to come.
Aired: 4/23/1961
The astronauts have trekked across the vast Venusian desert to return to their rocket. But as they near MR4, volcanic ash sets the jungle aflame - and MR4 is in the centre of the inferno.