"The Tenth Doctor's story comes to a close in this two-part finale that finds the Doctor (David Tennant) and his companion Wilf (Bernard Cribbins) taking on the malevolent Master (John Simm) and the rest of the Time Lords (led by Timothy Dalton) as the Time War creeps ever closer toward a conclusion. Billie Piper, Freema Agyeman and Elisabeth Sladen reprise their roles; writer-producer Russell T. Davies also bids farewell to the series."