Robot

With the Doctor behaving rather oddly after his regeneration, the Brigadier finds the research center under attack after a robot steals the plans for the new disintegrator gun.   Could the members of the mysterious Think Tank be responsible for the giant invader?  How sinister are the intentions of the shadowy Scientific Reform Society?   More importantly, can the Doctor recover in time to save the Earth from Atomic War?

• "Robot" marks the debut of the Tom Baker era.  Most fans in the U.S. probably began watching Doctor Who with Tom Baker and probably began by watching "Robot."

• This story also marks the beginning for a new companion, Harry Sullivan.

• When the character of Harry Sullivan was first conceived, it was unknown who would be replacing Jon Pertwee as the Doctor.  Harry was intended to be more of an action oriented companion for an older, less physical Doctor.  However, once Tom Baker was cast for the role, Harry's character developed more into a well intended but bumbling companion. 

• For the truly anal fans out there, you will notice a definite change in the length of hair of both Nicholas Courtney (The Brigadier) and Elisabeth Sladen (Sarah Jane) between this story and the previous one, "Planet of the Spiders."  And so it should be, there was a gap of 7 months between the filming of the two stories.