This was one of the more important stories of the original run of Doctor Who. It was the first story of the third doctor played by Jon Pertwee. It also marked a very different direction in the series at that time. Now the new doctor has been forced into exile on earth. The wonderful Tardis has been demoted to that of a lab. The Doctor forms a working relationship with U.N.T.I.L. and the show becomes something like the spy shows so popular at the time. Except with aliens of course. In this episode we meet the Autons and the Nestene Consciousness an alien race capable of animating plastic in various ways. While they are the menace of this arc they are also something of an also run as the episode is rightly more concerned with establishing the new Doctor and his relationships.