England, 1651. The highwayman known as The Nightmare is plaguing the land. But the Nightmare is not all he seems, and his fire-breathing accomplice who lurks in the shadows is clearly more than human… The Doctor, on the trail of an alien artefact, is brought face to the face with the consequences of his own actions. For once he encounters someone who won’t let him turn his back on the things he has done. But will the Nightmare be his friend or foe? It may well take till the end of the universe to be sure..