Two episodes featuring David Tennant as the tenth 'regenerated' Doctor Who. In 'The Christmas Invasion' Christmas trees and seasonal Santa Claus impersonators begin wreaking havoc on the residents of London. Meanwhile the TARDIS lands on Earth with a new Doctor aboard. The Doctor is not yet fully recovered from regeneration. An invasion of the planet threatens mankind and there's only the Prime Minister to battle it out. Also includes 'New Earth'.