The Doctor (Colin Baker), put on trial by the Time-Lords for violating the First Law, begins his defense. If found guilty of gross interference in the affairs of other planets, the Doctor must forfeit all his remaining regenerations. Perhaps he is a bit desperate at this point, in that he calls in his defence a companion that he has not in fact met yet. It seems he wishes to show the jury the good he will do in the future if he does not die in the present. Unfortunately, that’s not a hell of a lot of good, which is strange considering how many times in the past he has saved the whole damn universe. He chooses an incident from his own future, in which he and his new companion Melanie Rush (Bonnie Langford) arrive on the Space Liner Hyperion III in response to a distress call. Then they work to thwart a mutiny by the ship’s security officer Rudge (Denys Hawthorne), solve a murder mystery, and battle a hostile race of alien plants called the Vervoids.
They arrive in the TARDIS just as the series of murders are beginning. Among the suspects: a man who is lying about his identity and an agronomist transporting dangerous plants. Grenville (Tony Scoggo) is over-the-top overacting. Kimbur (Arthur Hewlett) dies hilariously. And there is Professor Laskey (Honor Blackman). When we first see her, she is reading Murder on the Orient Express. A bit obvious? Nearly everybody on the ship is guilty of something and has some kind of secret scheme.
The Vervoids look more like female body parts than the Triffids they are supposed to remind us of, and we are not supposed to make jokes about Pussy Galore. They were created on the planet Mogarin in the Perseus Arm of the Milky Way, by Laskey herself, to be a workforce to replace robots. One wonders why you would create slaves with vicious weapons built in. They are kind of scary but are defeated as soon as they are discovered, near the end of the story, and the Terror of the Vervoids features little in the way of terror from the Vervoids. Just as they decide to kill all the animal kind on board, and move on to decimate the planet Earth, they are gone—killed by heat and high levels of carbon-dioxide. You might think sentient plant-species would find heat and carbon dioxide perfectly lovely, but they bring on seasonal change and they end up a pile of dead autumn leaves. Having saved the human race by killing off the Vervoids, the Doctor is charged with genocide, even though it has not actually happened yet.
Bonnie Langford as Melanie Bush just sort of appears, already established as a companion despite the fact that we have never seen her before. She is such a bubbly, charming redhead that it’s hard to see her as having come directly from Les Miserables, which she had. Apparently, Mel’s backstory was supposed to be revealed in later episodes which never happened. We do know she comes from the village of Pease Pottage, and has almost total recall. She gets to scream quite a lot, like any companion worth her salt, but she can scream in the same key as the cliff-hanger musical sting, which is kind of cool. The story was released later without the Time-Lord trial scenes, which are something of a distraction in the other stories, but in this one are possibly the best part. There seem to be at least four writers to blame for all of this. The murder mystery on shipboard does evolve in decent fashion and Colin Baker, in his last story, is beginning to get the hang of it, and he actually seems to get along great with his companion.