In the days before a Doctor Who story had to have a huge monster in it to be considered for broadcast, this tale of Vulcan politics and power struggles proved to be a daring experiment. Pat Troughton is superb as the Doctor, with an early hint of the erratic nature that would become his trademark. The plot is expertly handled, with the Daleks being more than pepper pot shaped invaders; their cunning and evil genius is truly chilling. The animation medium also allows for some great lighting tricks to be added to scenes which might not have been possible on a live broadcast (a conveyor belt sequence being a prime example).
The script, by the prolific David Whitaker, is a good deal cleverer than anything Terry Nation had come up with at this point; he makes the Daleks more of a threat by manipulating the ruthless and misguided scientist Lesterson, who eventually snaps in the face of his own thuggish henchmen. This is the first time the Daleks kill their own kind, which is a terrible indictment of human greed and arrogance – although it is a little strange that it takes a pair of robots to point out this fact!
The DVD/BluRay extras include a startling rehearsal clip, which not only illustrates the tight production schedule of the show at this time, but also underlines just how far ahead of its time it was when tackling issues like power and tyranny. This is a genuinely great story that should not be missed by any fan of the classic series.