It is little surprise that Dr. Isaac Asimov named this as his favorite Dr. Who episode (though it actually comes as considerable surprise to learn that he even watched the series at all). Certainly the plotline and backstory development borrow liberally from the future society Asimov established in the Lije Bailey/R. Daneel Olivaw novels; it even works in references to the Three Laws of Robotics. The influence of an earlier book, RUR (Rossum's Universal Robots), also surfaces in exploring man's reaction to robots and their total absence of human body language (robophobia). Even the author's name, Karel Capek, is mirrored in that of the villain Taren Capel.
Newcomer director Chris Boucher (The Face of Evil) took the suggestion of longtime Dr. Who editor Robert Holmes and created an isolated, murder-mystery adventure as a vehicle to solidify the role of Leela, a companion he had introduced in the previous serial. Boucher drew from one of his favorite novels, Frank Herbert's Dune, to envisage the Storm-Mine setting. Effects director Peter Grimwade is immortalized in the episode thanks to a bit of ad-libbing by Tom Baker. Amongst the cast was David Collings as Poul, David Baile as Dask (Taren Capel), and Pamela Salem as Toos; Salem had actually been an unsuccessful applicant for the role of Leela.
Though not a milestone episode, I would name this is one of my favorite Tom Baker-era stories, largely because of its attention to detail -throwaway lines by characters reveal a rich tapestry of politics, history, and sociopolitical orders not always seen in a Doctor Who serial. We get a sense of the social "pecking order" on this nameless future planet from Uvanov's obvious disgust with Zilda's and Chub's family standing; at the same time we learn that the all-pervasive Company is not above covering up an employee's potentially embarrassing (or potentially expensive) past. Poul is a great study in contrasts: nobody on the Storm-Mine is the least suspicious of him until Leela turns up and likens him to a hunter. The insertion of D.84 is even more clever, and it illustrates just how inured this society has become to anything out of the ordinary. Uvanov dismisses Leela's assertion that D.84 can speak simply because "everyone knows" that particular class of robots can't speak.
In the same way, the crew dismisses the Doctor's theories about the murderer because "everyone knows" robots are incapable of such a thing. Robot behavior and robot Urban Legends are clearly at the forefront of even casual conversation, as evidenced in the opening scenes when we meet the entire crew idling away in the lounge. I also like the fact that the cast is a little more varied, racially speaking, from the usual spate of pale English actors. Helps to paint a more realistic vision of the future.
D.84 (Gregory de Polnay), the "undercover" agent, provides some wonderful back-and-forth dialogue with the Doctor and goes a long way toward widening the scope of the story. The robot's recount of the life of Taren Capel has made the murderer into a tragic figure before we've even figured out who he is, and it even gets to explore its own feelings of inadequacy; next thing we know it has even cracked a joke at the Doctor's expense. I always thought D.84 would make an ideal traveling companion -a sentiment I was surprised to learn was shared by many other fans. Its plaintive request to "please do not throw hands at me" is priceless. Definite homage to Daneel and Giskard there...
Though we, the audience, know the killer at the outset of this "whodunit," it is the question of who is the puppet master that takes up the scope of the story. This is also an uncharacteristically graphic episode; there are several strangulation scenes, a disturbing shot of a dead body being buried in a downpour of gravel, and blood all over the hand of the initial killer robot. There are also some chilling pyrotechnics; for my money one of the scariest scenes depicts another of the killer robots trying to break into the command deck, calmly announcing in its polite bureaucratic monotone that everyone has to die. Another great moment comes when Leela throws her knife squarely into the chest of an attacking robot -which then casually knocks it aside and keeps on coming. It is the first time we've seen anything even approaching fear on Leela's face.
The society that has been postulated is full of cause-and-effect: the Doctor's casual line about it being "the end of this civilization" is clearly no exaggeration. The characters, for all their feigned ease and opulence, are clearly not wholly comfortable with this robot-dependent society they have created for themselves, and as a result there is an omnipresent creeping paranoia that lurks just under the surface for most of the storyline. The parallels to the distrustful, robot-dependent society in Asimov's Caves Of Steel are obvious: mankind has gone and made another technological breakthrough which has become an indispensable part of daily life before everyone's really had time to adjust. Likewise, the Storm-Mine's carefully-ordered life is exposed to be a powderkeg; one little deviation from "everyone knows," and suddenly everybody's world is turned upside-down. This is especially apparent with Uvanov (Russell Hunter)'s newly-found "blow 'em all up" attitude, Poul's total mental breakdown, and Toos's hysterical sobbing (the latter also provides a great springboard for the audience to learn Leela's surprisingly tender and compassionate side).