The Doctor kicks off this new run of adventures by searching for his companion Clara - an Impossible Girl he's already lost twice. Together they find themselves battling monsters on distant alien planets, trapped in a Russian submarine with a deadly passenger, chasing terrifying ghosts, delving into the heart of the TARDIS, facing the Crimson Horror in Victorian Yorkshire, and coming face to face with an army of upgraded Cybermen. The action grows and the Doctor's oldest secret threatens to be revealed...