Spearhead from Space is an incredibly strong start to the Third Doctors era. It acts as a soft reboot,completely reformatting the show from adventures through time and space into, literally, a more grounded, earthbound era of the show. A bold move, and one that pays off. Pertwee is off to an immediately great start as the Doctor, Courtney returns as the Brigadier and John is strong as Liz Shaw. It is a great cast.

The script is strong, it runs at a good length and develops the Doctor well across the four episodes. The autons are a great threat and have a degree of creepiness to them, the threat builds well and manages to have both human and inhuman aspects to its threat.  Spearhead from Space boldly takes the show into a new direction and era in style and substance.