Romana initially resisted accompanying the Doctor (Tom Baker) on his mission to obtain the key to time, and she’s clearly unhappy about returning home. Their journey hits an unexpected snag, though, sending them instead to Alzarius. The inhabitants of this planet live within a wrecked spacecraft that is often enveloped in fog and share their world with native creatures known as the Marsh Men. These rough beings cause K9 some trouble while the Doctor investigates the situation and the reason for their unplanned stop on this foggy, swampy planet. Adding to the complications are Adric (Matthew Waterhouse) and his friends, who intend to seize control of the ship – even the iconic blue police box – from those currently in charge, despite the fact that no one aboard has operated it in generations. It seemed as if the main goal of this somewhat scattered narrative was to introduce new faces and bid farewell to others, which it manages adequately. The visuals are fairly simple, and George Baker’s performance doesn't help; the story feels repetitive, relying on a limited number of sets and costumes that have appeared before. Tom Baker seems to be losing some of his spark, and the show itself is starting to feel worn out. It’s fine to watch, but it isn’t one of the stories you’ll easily recall.

Source on TMDB