This was the third serial in Jon Pertwee’s first year as the Doctor, and was first sown between March and May 1970. Nicholas Courtney and Caroline John are along as the Brigadier and Liz Shaw, together with a load of UNIT soldiers.
The Doctor gets involved when something goes wrong with a returning Mars probe. While in our reality, this was shown while Apollo 13 was running into trouble, in the apparently near future world the UK has been more active in space travel, and has a moderately successful Mars programme. Anyway, the recovery ship sent to bring back the returning astronauts actually brings back something else altogether…
And so much fun follows. There’s a good bit of conspiracy, the Doctor flying a primitive space craft, people being kidnapped, wild use of radioactivity, and much more. It is a little long at seven episodes, but still works pretty well. The restoration job has worked quite well – there are some blotches in the recovered colour here and there, but overall it doesn’t look too bad, and certainly better than the black and white version I saw on UK Gold in the 1990s.
Extras are a little thin on this one. There’s the usual making of thingy, which has a long section on the Havoc stunt team, who made their Doctor Who debut on this story, and another in the “Tomorrow’s Times” series, looking at what the newspapers were saying during Jon Pertwee’s time in the show.
Not a particularly special release, but still worth watching.
 There is much discussion and debate about the dates of the UNIT stories.
 And doing some quite impressive facial expressions to simulate G forces