Season 4, Episode 15 - "Planet of the Dead"
11 April, 2009
In the first of four specials to mark the departure of David Tennant, The Doctor finds himself with six humans on the bus ride of a lifetime, involving various aliens, UNIT, crystals and gold and a # 200 bus. Along with the mysterious Lady Christina de Souza, the Doctor fights to stop a force that destroys planets from reaching earth. Special. Season 4, Episode 15 – Aired: 4/11/2009
