S4, E103: It's the Tenth Doctor's final journey - but his psychotic nemesis the Master has been reborn, on Christmas Eve. With both determined to cheat death, the battle rages from the wastelands of London to the mysterious Immortality Gate. Meanwhile, the alien race Ood warn of an even greater danger approaching, as a terrible shadow falls across the entire Universe. David Tennant stars as the Tenth Doctor and guest stars include John Simm, Bernard Cribbins, Catherine Tate, Timothy Dalton, David Harewood and June Whitfield. The End Of Time, Part One is written by Russell T Davies and directed by Euros Lyn. The producer is Tracie Simpson.