Ian’s trial is concluded and Yartek is defeated. All in a day’s work.
“The execution is scheduled for when the pointer reaches the star.”
In the end the conspirators indict themselves. It is a nice twist that the wife of the murderer was involved. She also kidnapped Susan. Despite accidentally giving away her involvement, she did remain loyal to the conspiracy by naming Ian as the mastermind behind the murder and theft. By this point the chief interrogator no longer believes Ian is involved, but the burden of evidence still rests on The Doctor and he has none that can free Ian. However, now that the trial is concluded, all the evidence goes back in the cabinet and our heroes plan a stakeout where they catch the final man in the conspiracy: the prosecutor. With the exception of the wife, none of these characters have been memorable, so names really escape me.
The travelers return to the island with the pyramid to find Arbitan dead and Yartek in control of the machine. He takes all the keys and tricks Ian into giving him the final key. Ian, seeing through the guise, gives Yartek the fake key that was found in the jungle. This causes the machine to explode, killing Yartek and his Voord associates.
In the closing sequence, The Doctor addresses some of the concerns I had regarding a machine controlling the consciousnesses of humans. He flat out states that he doesn’t like it. “Machines can make laws but they cannot dispense justice.” If he took exception to this idea, then what would he have done if Arbitan hadn’t been killed? Perhaps The Doctor would have convinced him to destroy or modify the machine. It all works out for the best regardless.
This entire serial has been a mixed bag. I suppose for me only half of it works. The Sea of Death, The Velvet Web, and The Snows of Terror each had some interesting ideas while the latter story touched on some dark material and the cave sequence was rather fun. Again, I can’t quite get over how much I enjoyed the ice knights. The other three episodes just seemed slow to me. The courtroom drama of the previous episode and the investigation in this one seemed rather simplistic, but that’s probably because I’ve been watching a lot of Miss Marple and Poirot lately. Not to knock Terry Nation too much, but he does seem to be better at coming up with ideas and concepts than at executing them consistently well. The Daleks worked, and perhaps that is why this one feels so disappointing. His previous effort was better paced and more interesting. The lack of sufficient world-building in this story makes it suffer. Truth be told, The Keys of Marinus is probably just too long. Perhaps Nation should have followed the rule of three in mythology. Three keys instead of five would have made the story shorter and possibly tightened up the narrative. Regardless, The Keys of Marinus is now over and we will be moving on to better, Lucarotti-penned episodes.