Peter Capaldi returns as the mad-cap Doctor for another series of exhilarating adventures. Accompanied by his fearless companion Clara Oswald, the duo must overcome dastardly foes, both old and new, in order to protect the things they care about most. Has The Doctor's luck finally run out - or will he and Clara be able to save the world once again?. Peter Capaldi returns as the mad-cap Doctor for another series of exhilarating adventures. Accompanied by his fearless companion Clara Oswald, the duo must overcome dastardly foes, both old and new, in order to protect the things they care about most. Has The Doctor's luck finally run out - or will he and Clara be able to save the world once again?