This is a curious box set, packing together two of the best-ever Doctor Who serials and their less well-regarded sequel. Here we will focus on the first two discs.

Following Troughton's trial and effective execution for his crime of curiosity, Pertwee's newly-born Third Doctor wakes to find himself exiled to Earth, unable to work his TARDIS, and trapped in the employ of a parmilitary group called UNIT.

It is in Pertwee's second serial, The Silurians, that we see the real friction and significance of his new position. At the and of all-time great Doctor Who writer Malcolm Hulke (co-author of The War Games), Doctor Who becomes an adult morality play, steeped in politics and cultural ethics.

As it happens, humans weren't the first sapient people on this planet. Long before our ancestors came out of their burrows, the Earth was the domain of a race here dubbed the Silurians. These were a reptile people, warlike but rational -- and in some cases actually reasonable, if one can get past a mutual fear.

Can we, though, get past that fear? Can they? Can the Doctor hold back the military and biological might of two paranoid races, and find a peaceful solution? Or will this struggle end in total genocide -- of either their race, or our own?

The Silurians was new territory for Doctor Who, and even today stands as one of its crowning achievements. Never again would the show explore such a complex struggle in such a delicate way. If you want to know what Doctor Who can be at its very best, The Silurians is a must-see.

The second serial in this set is a fun follow-up, also from the typewriter of Malcolm Hulke. There's nothing new here, except for the addition of the Doctor's dark counterpart, the Master. Over the course of the previous season we met the Master and followed the Doctor and UNIT as they tracked him down and eventually caught him. Now he is in captivity, yet still pulling the strings of his captors. Meanwhile the Sea Devils, aquatic cousins of our friends from the previous story, decide that they want to retake the planet for their own. It's good stuff, but we've been here before and the story knows it.

The last serial in this set comes from over a decade later, and the start of Fifth Doctor Peter Davison's final season. Here the Silurians and the Sea Devils attack a human sea base, in an even more blatant parable for cold war friction. Doctor Who fans hate this one. It's not terrible; it's just sort of unnecessary.