Doctor Who: The Newbies Guide
Spearhead from Space
This is the first story in Season Seven.
This incarnation of the Doctor is brand new. In The War Games the Doctor's people (the Time Lords) sentenced him to exile on Earth and to change his appearance.This story marks the start of this sentence.
Brigadier Lethbridge-Stewart is the commanding officer of the United Nations Intelligence Taskforce (UNIT). He has worked with the Second Doctor to defeat threats to Earth on two occasions (in The Web of Fear and The Invasion, but is not aware that the Doctor's appearance can change.
Elizabeth "Liz" Shaw is a new character and this is her first appearance.
Recurring and Historical Characters
The United Nations Intelligence Taskforce (UNIT) is an organisation devoted to protecting Earth from extra-terrestrial threats, In The Invasion, the second Doctor teamed up with them to prevent an invasion by the Cybermen.