Three videos in one review? Well, let me give it a shot!
Full Circle: In Adric's debut story, the Doctor and Romana go through a CVE (Charged Vacuum Emboitment), en route to Gallifrey, and land on the planet Alzarius. The planet is experiencing Mistfall, a bubbling of the mists that bring out the Marshmen.
Adric is caught between sides. On one hand, he feels stifled by the conventions of society, but the Outlers, led by his brother Varsh, see him as part of the establishment. Naturally, there is only one place for him, as the viewer will see at the end.
The paralysis of the Alzarian "Type D Oligarchy" is painfully aware, as the Deciders have enforced a policy of deliberate ignorance on its citizens, and are guilty of "willful procrastination." As Login says: "A little patience goes a long way." The Doctor replies: "Too much patience goes nowhere." The strongest supporting character is George Baker who plays the decisive Decider Login, the most respected member of the community, who in the end gets something done. Second place goes to June Page as Keara, Login's Outler daughter, who would have been an ideal companion, but Nyssa came along in Keeper Of Traken.
This is a story with a mystery that is gradually revealed bit by bit, and it works effectively to that effect. Clues include Decider Nefred's pained reaction on seeing the system files, Draith's dying words: "Tell Dexeter we've come full circle," and the pain shared by the Marsh child, being dissected by Dexeter, and Romana, who has an alien protein injected in her from a spider bite.
The Doctor's carelessness of leaving the Starliner door open leads to the Marsh child's entering the Starliner, subsequent capture, and death. Surprising for his character. And the rising of the Marshmen from the swamp is effectively realized. And those marsh spiders are creepy-looking!
State Of Decay: Still in Exo-space, The TARDIS lands on a planet, "a typical medieval scene," dominated by a "protective castle with village dwellings huddled like ducklings around their mother." Reading, science, and knowledge are capital crimes, but that doesn't stop a secret rebel movement.
It turns out that the castle is actually an Earth ship that got [pulled] into E-Space a millennium ago. And who are the "Three Who Rule, apart from being King Zargo, Queen Camilla, and Councillor Aukon? A cloud of bats, courtesy of effective stock footage, and fuel tanks filled with blood gives the Doctor "a suspicion, but it's too horrible to think about."
The Doctor has a good line when Romana asks him how he knew there was another planet in E-Space: "Knowing's easy. Everyone does that ad nauseum. I just hope."
Debit: the Great One is only seen as a large claw groping the surface. And the Wasting is never explained. Still, a steady story in the trilogy.
Warrior's Gate: The TARDIS lands at Zero Point, the intersection between N- and E-Space, which is white nothingness (q.v. The Mind Robber). They run into a privateer named Rorvik, who has a ship carrying time-sensitive slaves, Tharils, "leonine mesomorphs" as described by Romana.
There is a wonderful surrealness of the Doctor walking through the black and white photos and drawings that is the link to the Tharil past. And the concept of a rapidly contracting dimension leading up to a mathematical disappearance is a novel concept. Episode 3's cliffhanger is effective, as the past quickly becomes the present, and the Doctor, surrounded by Tharils at the banquet table in one instant, suddenly finds himself surrounded by Rorvik and his crew.
There is snappy dialogue throughout. Lane: "There's a hole that you can climb through. Matter of fact, I just did." Or the Doctor: "We'll burn that bridge when we come to it." When Rorvik orders Romana hooked up, Packard, wondering of her abilities, says: "If she isn't time sensitive, she'll burnt to a frazzle." Lane: "That's how you tell." And Aldo and Royce are cariacatured union employees, lazy and apathetic, who don't care about bonuses being lost since they're on the "all out contract." And Biroc's defense to their enslavement of and later, by humans: "The weak enslave themselves." He also says that "the universe is our garden."
Errors are K-9's ears disappearing and reappearing in the first two episodes, and the Gundan Robot's axe falling on the Doctor's back without any injury to him.
This is the first of John Nathan-Turner's transitional trilogies. Adric is introduced, and the Second Romana and K9 Mark II are phased out. There would be a succeeding trilogy, also transitional, which would affect the Doctor personally.