The one where a man rips his trousers.
The premise starts out as the myth of Theseus and the Minotaur in space. A group comprising three teenaged boys and four teenaged girls from the planet Aneth are being taken to the planet Skonnos as sacrifices to Nimon, a powerful alien with the appearance of a bull-headed man who lives in the centre of a vast labyrinth. Among them is the hero Seth, who is going to defeat Nimon once and for all.
Unfortunately for Aneth, Seth is only a Badass on Paper: the truth behind his reputation consists of a little bit of luck and a great deal of exaggeration on the part of his friend and fellow captive, Teka. Fortunately, the Doctor and Romana have come to help. They're up against the magnificently hammy co-pilot of the slave ship (Malcolm Terris), the even more fantastically hammy high priest Soldeed (Graham Crowden), and the tremendously hammy Nimon itself (Clifford Norgate). Romana gets captured and shoved into the labyrinth with the sacrifices, while the Doctor tries to find out what's going on and plan a rescue.
The Doctor meets Soldeed, who tells him that in return for the sacrifices, Nimon has promised to restore the Skonnon Empire to its former glory. Meanwhile, in the labyrinth, Romana and the sacrifices encounter Nimon, and begin to discover that there is much Soldeed hasn't been told, and that the Skonnon Empire's glory is very low on Nimon's true list of priorities. Instead, the Nimons are a planet-devouring race, and they've built a black hole teleporter that will transport the entire Nimon population to the Skonnon Empire's cities.
The co-pilot is killed by the Nimon, overacting so hard that his trousers visibly split. Graham Crowden (who, incidentally, was cast as the Fourth Doctor but turned the role down) makes up for the co-pilot's death by overacting for two. When he dies as well, K-9 saves the day.
- All There in the Manual: The pilot and co-pilot are named Sekkoth and Sardor respectively.
- Apocalypse How: Crinoth has already experienced what seems to be a Class 5 or 6 when we first see it. It subsequently becomes a Class X when the Nimon blow up the planet to give them energy for their teleportation system.
- Artistic License Astronomy: According to the Doctor, an object that is only 96.4 km across weighing 220 million tonnes is not an asteroid, but a planet (in fact the opposite is true).
- Asshole Victim: The co-pilot from part 1 and 2 and he practically deserved the consequences he received.
- The Atoner: Sezom
- Badass on Paper: Seth. He never wanted to be a hero, and now is less worried about what happens to himself than about letting down the people, especially Teka, who are counting on him.
- Big Bad Wannabe:
- Soldeed looks and talks, basically, like Ming the Merciless, and thinks the Nimon will enable him to become an interstellar conqueror. He's also supposed to be a great scientist, but all his powers and abilities come from the Nimon. This throws him for a loop when a real scientist (the Doctor) turns up.
- Likewise Skonnos is bluffing Aneth into handing over prisoners based on their reputation as a badass intergalactic empire, when all they've got is a single spaceship that barely works.
- Bottle Episode: Sets recycled from various other BBC productions and from previous stories, a bit of slowmo with some borrowed equipment from the sports department, some CSO, some fireworks, some teenage extras. The focus is on a small cast of ridiculously campy villains and a lot of Ham and Cheese. This was to save money for the next serial, "Shada", but...
- Bull Seeing Red: The Doctor does a bullfighting routine with his coat to distract Nimon.
- Call-Back: When the Doctor gives Romana the task of examining the Nimon travel capsule, the first thing she does is borrow his teaspoon.
- Camp: One of the series' most glorious examples.
- Corpsing: Graham Crowden, who plays Soldeed, does this after he gets fatally shot. However, it actually comes across as being perfectly in character, so he gets away with it by turning it into some kind of crazy chortle.
- Deconstructor Fleet: Romana notes through word play that the head guys have a "power complex".
- Dirty Coward: The co-pilot from part one and two. He tries to pin the blame for his mistake on Romana but Soldeed saw through his lies and sent him to be killed by the Nimon. When the co-pilot tries to save himself by telling Nimon he "brought" the sacrifices to him, the Nimon can tell that he's a liar and a coward and kills him first.
- End of an Era: Due to the cancellation of "Shada", this marked the end of several eras:
- It was producer Graham Williams' last story, as well as the final script to be edited by Douglas Adams.
- The final story in which David Brierley voiced K9.
- The final use of the original 1963 arrangement of the "Doctor Who Theme", from the 1967 remix by Delia Derbyshire, as well as the last use of the diamond-shaped series logo and "tunnel" opening sequence by Bernard Lodge, which had been in place (with some modifications) since The Time Warrior. The opening credits image of Tom Baker, now close to six years old, is also retired.
- The last story to be scored by composer Dudley Simpson.
- The final appearance of Tom Baker wearing his "original" trademark scarf and coat before they were replaced in the next story by their burgundy counterparts.
- Evil Is Hammy: Soldeed is infamously campy. So much so that his confrontation with Romana has a dance remix. "MY DREAMS OF CON-QUEST!"
- Evil Sounds Deep: The Nimon have deep, booming voices.
- Failed a Spot Check: Apparently a Nimon racial characteristic. Not only do some of the Nimon fail to see Romana and Sezom hiding behind a translucent wall, two of them fail to notice the Doctor open their travel capsule, look in on them, slam the door, and bounce them back to their start point. Even by the standards of Classic Who villains, that's pretty bad.
- Fauxlosophic Narration: The Nimon's speech, according to Soldeed.
- Frickin' Laser Beams: Uniquely, the Nimons fire lasers out of their horns.
- God Guise: The Nimon's modus operandi when it comes to their invasion plans.
- Ham-to-Ham Combat:
- Heroic Sacrifice: Sezom.
- Human Sacrifice: The cargo are human sacrifices, in the same manner as the Athenians in the legend of Theseus.
- Hypnosis-Proof Dogs: The Doctor et al. are in a Minotaurlike maze where the walls keep moving about, but the Doctor's dog-shaped Robot Buddy K9 just goes right through the wall to freedom because he can't see it.
- Inside a Computer System: The Labyrinth is actually a giant computer, while the Mobile Maze aspect is the computer's circuits moving.
- The Klutz: Every time the Doctor tries doing anything in this story, he ends up mildly hurting himself through his clumsiness - electrocuting himself on the TARDIS console, trapping his fingers slightly in machinery, injuring himself punching something...
- Large Ham: Graham Crowden as Soldeed pretty much defines this. See also: Tom Baker, as ever, and Lalla Ward, to an extent.
- Last of His Kind: Sezom. The first Nimon pretends to be this (as a way of tricking people into helping him - if there's only one, then they can eventually pull a You Have Outlived Your Usefulness on it), but it later turns out to be a Blatant Lie.
- Life Drain: How the Nimon feed. It leaves people, and entire planets, as desiccated husks.
- A Load of Bull
- Mickey Mousing: When the Doctor starts decorating the labyrinth with the star stickers, Dudley Simpson breaks out the glockenspiel. Later in the story he quickly flashes a grin at someone in mid-flow which is underscored by a glockenspiel chord in the music as well.
- Milking the Giant Cow: The actors in the Nimon costumes are really going for it. Oh, and no jokes about "giant cows."
- Mobile Maze: The alien Nimon demand sacrifices from the Skonnon Empire to provide for them. They use victims from the planet Aneth, who find that the walls seal behind them. It turns out the labyrinth is actually a giant computer and the changing walls are the circuits making connection. The entrance is actually a hologram of a wall.
- Mood Whiplash: Despite the nasty implications of what the Nimons do to unsuspecting planets, the story is generally quite soft and comical for the most part... until the final episode, where Romana is accidentally teleported to the burnt-out, almost totally depopulated planet Crinoth, the previous victims of the Nimon. After that, the story's mood becomes surprisingly grim and apocalyptic.
- Negative Space Wedgie: The TARDIS encounters one in the first episode which turns out to be a side-effect of the black hole travel system.
- No Body Left Behind: Soldeed's corpse inexplicably disappears from where it fell shortly before the labyrinth explodes.
- Noodle Incident: At one point, Seth confesses to Romana that he's "not even a prince", just a young runaway who was found by someone (presumably the servants of Aneth's king) and "made up some story" to avoid being sent back where he came from. This story must have involved him claiming to be the king's long lost son, but we never learn why he ran away, nor why he was so desperate not to be sent home that he concocted such a tale.
- Our Wormholes Are Different: Black holes used as conduits for interstellar travel. (Though the expanded universe pointed out, only Nimons have done that.)
- Pantomime: This serial was originally broadcast over Christmas; it's a Whole Plot Reference to a legend but full of ridiculous characters who break the familiar plot; it features over-the-top and hammy performances from some actually very good actors cracking themselves up; Romana is the hero in this one and dressed in sexy historical male clothing in the manner of the Principal Boy; it's made on the cheap but with some really fabulous Stuff Blowing Up; the Doctor is mostly relegated to comedy pieces and slapstick sequences done either solo or playing against K-9 and the TARDIS (props) in the manner of the solo skits done in panto by famous guest stars; Soldeed's "Lord Niiimon, Lord Niiiiiimon!" catchphrase has a similar delivery to the panto "he's behind you!" routine; an actual "he's behind you!"-style routine happens in the story in the sequence when the Doctor is evading the Nimon in the control room... Doctor Who fans love to criticise poor stories by calling them 'pantomime' but this one may actually be intentionally a panto.
- Pinball Protagonist: The Doctor spends most of the story fighting the Negative Space Wedgie while stuck in the TARDIS while Romana does the stuff the Doctor would normally do. He does help create a device for affecting the gravity problems but it's clearly shown Romana could have done it just as easily on her own and would have done it without his help. He is present while the Anethians get out of the labyrinth but K-9 is the one who actually does all of the work, and the Doctor even argues with K-9's solution and is proven wrong. Even getting Romana and K-9 there in the first place can't be attributed to him, since they all got pulled down there by the gravity device. The only things he does that affect the plot are getting K-9 back from Soldeed and discovering the Nimons' ship. This was likely an intentional attempt to control Tom Baker's level of involvement, as he'd been getting very controlling and unstable at the time.
- Planet Looters: Nimon.
- Power Crystal: putting a special crystal into the ceremonial staff the Nimon give to their spokespeople turns it into an energy weapon that can stun the Nimon.
- Red and Black and Evil All Over: The Nimon have black fur/skin with bright red eyes.
- Shout-Out: The line "I'm glad I reminded them to paint their ship white; last time anything like this happened, completely forgot, caused quite a hoo-ha," is another reference to Greek mythology, specifically when Theseus forgot to paint his flag white, causing his father Aegeus (who had an agreement with Theseus to paint his flag white if he came back alive) to jump off the palace in despair.
- Shout-Out to Shakespeare: The Doctor quotes Hamlet in saying, "Oh my prophetic soul".
- Significant Anagram: Most of the character and place names are derived from their mythological counterparts.
- Smug Snake: Soldeed, full stop.
- Space Pirates: The Doctor and Romana are accused.
- Technology Upgrade: The Nimon claim they're going to provide advanced technology to the Skonnos, but in actuality the Nimon are going to denude the planet of everything.
- Unaccustomed as I Am to Public Speaking...
- Unrealistic Black Hole: The Nimons use black holes to power their technology and as wormholes to travel the universe.
- Vestigial Empire: Skonnos. They were once great, but they blasted themselves into irrelevancy in a civil war. The Nimon gains their aid by promising to help them rebuild their tech base to the point where they can start a new empire.
- Villainous Breakdown: Soldeed does not take the realization that he's been had well.
- What Could Possibly Go Wrong?: lampshaded:ROMANA: Don't you think that's a bit dangerous?
DOCTOR: No, I don't. What could possibly go
(Lurch. The Doctor falls.)
DOCTOR: Ow! Wrong. You know, I've simply got to stop saying that. Every single time I say what could possibly go wrong, something goes
- What Happened to the Mouse?: Shortly after entering the Complex, Romana and the young Anethans come across the Nimon's larder, where those sent to Skonnos in previous years are kept in suspended animation until it is their turn to have their life forces drained. However, though only one of the Anethans already in the larder is seen to die (killed by a stray beam from the Nimon's horns) the Doctor and Romana only emerge from the Complex with Seth, Teka and the others who were in the last consignment of sacrifices.
- Whole Plot Reference: To the legend of Theseus and the Minotaur. And the Doctor was apparently involved in the original version of the tale at some point in his lives, given a comment he makes during the ending.
- Wide-Eyed Idealist: Teka.
- The X of Y
- You Have Outlived Your Usefulness: The people who aid the Nimon always think that they can pull this, as there's only one of them. Then several million of them show up and reverse the trope.
- You Rebel Scum!: Parodied with the co-pilot who addresses his prisoners as "weakling scum" every time he speaks to them.
- "You meddlesome hussy!!"