The Doctor and UNIT come under attack by an alien force, and not even the Time Lords can help. They too are under threat from a black hole in space. The only way they can help the Doctor is to break the first law of Time and allow him to help himself.
Starring Jon Pertwee, Patrick Troughton and William Hartnell -- as The Doctor!
Original BBC Video DVD Release, Region 1 (USA) edition. Disc and case are in VG condition. FREE SHIPPING within the USA.