Trapped on the distant world Marinus, the Doctor (William Hartnell), Susan, Barbara, and Ian are forced to undertake a planet-wide search for the four keys to the Conscience of Marinus, a powerful mind-controlling machine. 145 min. Standard; Soundtrack: English Dolby Digital mono; Subtitles: English (SDH); audio commentary; featurette; photo gallery; DVD-ROM content; interview. **William Hartnell stars. 145 min.**
Trapped on the distant world Marinus, the Doctor (William Hartnell), Susan, Barbara, and Ian are forced to undertake a planet-wide search for the four keys to the Conscience of Marinus, a powerful mind-controlling machine. 145 min. Standard; Soundtrack: English Dolby Digital mono; Subtitles: English (SDH); audio commentary; featurette; photo gallery; DVD-ROM content; interview. **William Hartnell stars. 145 min.**