Fresh from their visit to medieval China, the travelers come to Marinus. There they uncover a complex mystery: a strange structure with no obvious entrance; a sea of acid, and several minisubs piloted by humanoids in wetsuits — the Voord. This sets up the frame story for the plot, which reads like something I would have developed as an RPG gamemaster in high school: The building houses the Conscience of Marinus, which has the ability to control the thoughts of everyone on the planet. The machine is inactive, its control keys hidden away by its guardian, Arbitan. However, Marinus is under threat by the Voord, and the machine is both the biggest threat to the planet and the only weapon that can defeat the Voord. So the travelers are coerced by Arbitan to obtain the story’s maguffin: the keys to operate the mechanism. Most of the remainder of the plot consists of small single-episode setpieces that involved a subset of the characters, as they split up to find the keys. Unfortunately, the sets and costumes for Marco Polo ate up much of the design budget, and the wide variety of settings for each episode no doubt required further economies, so that the locations for the serial come across as particularly chintzy. Since the serial is divided up into mini-adventures, it makes the most sense to me to review each on its own. One interesting element is the wrist-transporter, which allows its owner to travel through space in an instant; a handy plot device!
The Velvet Web is a classic sci-fi plot: the apparent paradise that turns out to be far different than it appears. This is due to a hypnotic trance created by several brain-stalk creatures that appear to be distant cousins of the Gamesters of Triskelion. This episode introduces us to Altos and Sabitha, Arbitan’s servant and daughter, respectively, who are involved in later episodes. Otherwise this episode is not particularly noteworthy, apart from the fact that Barbara ends up as the hero, as she defeats the aliens’ attempt to induce hypnosis and she manages to destroy them with the help of Sabitha. At last the women get something to do!
The Screaming Jungle is even less interesting — the team end up in a jungle of mobile plants and flimsy traps, set up by the guardian of the key, a man named Darrius. Ian and Barbara have to figure out a puzzle to get the key and escape, but much of the tension is weakened by their ability to pop out whenever they need to with a twist of their transporters. At least the hypnosis of the previous episode was more insidious.
The Snows of Terror is meant I think as a character study; Ian and Barbara are rescued from the cold wasteland in which they materialize by a taciturn loner named Vasor, who turns out (surprise surprise) to be not entirely trustworthy. Cellophane caverns and stock footage of wolves are the main antagonists here, along with the Slow Moving Silent Knights Who Scream, who turn out to be the guardians of the key. Another ho-hum episode.
Sentence of Death turns out to be the saving grace of the serial, however, as this is in my opinion the best episode of Dr. Who to this point in the series’ history. Ian appears in the location of the 5th key (albeit alone, for some reason), and find himself in the wrong place at the wrong time. Framed for murder, he must go on trial for his life, in a society in which the accused are presumed guilty. The alien courtroom will be a commonplace among sci-fi television, but it is played to good effect here, as the danger to Ian is palpable. This episode also sees the appearance of the Doctor familiar to fans of the series. Hitherto Hartnell has played the Doctor as a curmudgeonly, often cynical opportunist, perhaps playing off his character’s back story as a fugitive wanderer. In this episode, however, the Doctor is upbeat, even brash, confident in his ability to get Ian off. This marks an important change in the personality of the Doctor, one that will have great resonance in later stories and seasons.
The following episode, The Keys of Marinus, continues the melodrama and Ian is finally freed by a combined effort of the Doctor and all of the companions. Terry Nation does a good job maintaining suspense and providing a false resolution before coming to the denouement. It’s good to see all of the companions play an active role at the same time, and Nation plays with the now-established characters (as he did in several preceding episodes) by having Ian, usually the man of action, forced to cool his heels and wait for the others to rescue him.
By contrast, the final stage of the story is anticlimactic; the Voord take over the tower of Arbitan and a struggle for control of the Conscience of Marinus ensues. Nation plays well with a twist introduced earlier in the plot, but the sequence of events is predictable, and the outcome of all the shenanigans is merely that nothing happens, other than the characters manage to escape Marinus. In short, an uneven story with a few moments of brilliance.