Never have so many people worked so hard to create so little as they have in Terminus. This story from the 20th season is certainly on of the most uneven stories of the Peter Davison era which excels on some points and dies badly on others.
I've gotten used to the occasional padding to fill the story and sometimes have enjoyed it. Smarter authors will fill the padding with bits of back story or character scenes but Steve Gallagher fails to come up with anything interesting or original to keep the story moving. In a story that has a full TARDIS crew, the Doctor, Nyssa, Tegan and Turlough, plus two pirates, Kari and Olvir, and various guards, prisoners and the Black Guardian it should be a whirl wind adventure but it completely falls flat after the first ten minutes of the first episode. The Black Guardian has forced Turlough to damage the TARDIS and it crash lands on a ship just as it is being hit by raiders. The TARDIS crew is separated and have face various dangers. This is a real explosive start but then absolutely nothing happens until the third episode. It's just a bunch of one dimensional characters going through a predictable routine that doesn't add much to the story.
The raiding party is dressed with comical helmets, capes, and skin tight jump suits that make them look more like they are from a futuristic telling of "Babes In Toyland" and fails to give them any credibility. Olvir, who claims to have combat training, panics and hides in a corner after their first violent encounter. Later he barely manages to handle a worn and battered Valgard and still completely misses the Garn taking off with Nyssa just a few feet behind him. The character is so badly written I couldn't help but wonder if it was originally supposed to be Adric in the story but hastily rewritten and readjusted to fit a different character.
As a stark contrast from the look of the raiding party the Vanir, guards on Terminus, are amazingly catching in their styles. The skeletal like armour makes and odd clicking sound as they move and their masks give them a powerful presence when they enter the scenes.
Another odd pair of characters added after a few episodes are the Garm and Bor. The Garm is a huge creature with a dog like head and glowing eyes that has been forced to serve the Vanir. Unfortunately it only looks good but when it talks you can sadly see the thin veil meant to cover it's mouth and the face of the operator inside. Less would have been more with this character. On the other hand Bor is more of the average guy type character who just wants to stay loyal to his job and has paid for it with pain and suffering from radiation sickness. He's the most interesting character brought in during the story and gets all the best lines. "Am I dead?" he asks. "No? Well, good, cause I was hoping for something better on the other side."
Nyssa gets the worst writing of all the companions in this story. She's gone from an experienced space traveller with a high IQ to someone who, when hearing footsteps approach, cowers into a little ball and hopes for the best. Then she spends two episode screaming in fear and getting stripped down to her undies but manages to come back in the final episode as a genius scientist who is willing to brave out the rest of Terminus and stop the plague.
Tegan and Turlough go no where in this story. All they have to do is spend time together and scowl at each other to get them to do anything. There is so much that could have been done with the Black Guardian haunting Turlough in this story it's sad they way both of them are turned to one dimensional roles.
One of the strengths of this story, and there are very few of them, is the design of the ships and Terminus. That skull symbols on the doors are very powerful and give an uncomfortable feeling to the location. There is also enough dressing and changes in set dressing that you never get the "we've been down this corridor before" feeling.
So why was this story done? Apparently the idea had been rejected two years earlier but accepted for the anniversary season. As part two of the second Black Guardian trilogy the story fails to advance the Black Guardian plot in any way. The structure of a trilogy leads to the second act being a big cliffhanger but there is no advancement to the umbrella story here. The best bet is to just skip the story between the classic Mawdryn Undead and the creative Enlightenment and just make it Black Guardian two parter.