Aeons ago, a genetically-engineered polymorph was the ultimate warrior, able to change its own shape to "suit its terrain and deceive its enemies", and also emotionally crippling the enemy to disorientate them. Sealed away inside a Genetic Waste Pod, where it remained for three million years, it was eventually able to escape, unfortunately for the blissfully unaware boys from the Dwarf, just as the Red Dwarf is passing by. The GELF enters the cargo bays by chewing a hole in the hull, and begins to seek out victims, taking dozens of different forms as it goes, such as an alarm clock, a rabbit and a bouncing beach ball.
Meanwhile, in the Officer's Quarters, Dave Lister cooks his "Shami Kebab Diablo" using a whole tub of chilli powder - a dish which he is proud to point out that once put Olaf Petersen in sick bay for a week - for himself and Cat. This is Lister's attempt at more 'classy' dining, and he wanted to do something a little 'different', involving using items from the medical unit; this includes using an embryo refrigeration unit to store the food, using surgical trays as plates, using scalpels instead of knives, and a bovine artificial insemination syringe to serve lemon juice. Cat is disgusted, with him calling it more of an autopsy than a meal, and he leaves. Kryten then enters and finishes off the cleaning of the Officer's Quarters with his Groinal Attachment, accidentally sucking up a penny in the process and shaking violently.
When the Shammi Kebab Diablo suddenly jumps off the plate and around Lister's neck, Lister throws it across the room. Putting on his boxer shorts, they suddenly begin shrinking around his groin, and Lister falls to the ground as he attempts to remove them. As Lister pleads for Kryten to help take them off, Arnold Rimmer walks in and gets the wrong impression, saying that he's not surprised since Lister will bonk anything. The boxers then shape-shift again, this time turning into an anaconda - Lister's second worst fear - and then into an "eight foot tall armour-plated alien killing machine" - his worst fear - taking Lister to the very limit of terror. The polymorph then drains Lister of all his fear with a plunger-like tongue on Lister's forehead. It then quickly escapes from the quarters, leaving Lister unconscious.
The others get Lister up to the Science Room, where Kryten runs some tests and deduces that Lister has been drained of all his fear. After Kryten explains what the polymorph is, and that it feeds on negative emotion, Lister wakes up wanting to fight the polymorph - saying they should get out there and "twat it" - and also fight everybody else present. Kryten sedates him, and Rimmer says their plan should be to "run away", and so they go down to the shuttle hangars. As they load up supplies from the cargo bay, Cat is forced to run from their own accidentally-fired heat-seeking bazookoid fire, although with his lightning reflexes Cat is able to trap the fire-bolts in an airlock.
Full of pride, Cat is seduced by a woman, Genny. Genny reveals herself to be the genetic mutant, but Cat doesn't click on, and after offering sex and inflating his ego, proceeds to drain Cat of all his vanity. This turns Cat into a very out-of-character drunken, smelly tramp with a low opinion of himself. Kryten and Rimmer then find him, and Rimmer tells Kryten it is his fault as he let Cat run off alone, causing the mechanoid's guilt chip to go into overdrive. Rimmer reveals himself as the Polymorph and drains Kryten of all his guilt, breaking Kryten's programming. Kryten immediately develops a selfish and insulting demeanor, and no longer cares about his crew-mates.
They then go back up to the Science Room and meet up with Lister to find Rimmer's mother apparently having just had sex with Lister, which an amused Kryten points out contradicts Arnold's "very prim, very proper, almost austere" view of her and further enrages Rimmer. He initially tries to keep his cool, but between Lister's attempts to provoke a fight, Kryten's taunting, and "Mrs. Rimmer" telling him how Lister made love to her using Alphabetti Spaghetti, Rimmer blows his top and the polymorph (who was in Mrs. Rimmer's form) drains Rimmer of all his anger.
The Dwarfers then discuss their next move, and Holly tries to rally them to fight the polymorph while it rests after its four-course meal, however being drained of their emotions means they don't get very far in preparing a plan of attack. Lister is determined to take out the Polymorph through the most violent means possible (especially if he gets the chance to kill himself in the process), even suggesting letting the others ambush while it eats him to death, or strapping on a nuclear warhead to his head and headbutting it. Rimmer is now a glasses-wearing pacifist donning a t-shirt which reads 'give quiche a chance' who plans to hit the Polymorph with a leaflet campaign followed by benefit concerts; Cat feels he is too worthless to venture an opinion; and Kryten is too busy dishing out insults and working out if he can survive by sacrificing the others to offer any kind of valid opinion. It's eventually decided, in lieu of an actual plan, to head down to face the polymorph and hope for the best.
The Dwarfers go down to the cargo bays to confront the polymorph, but they accidentally release the still-active heat-seeking bazookoid energy bolts which Cat had evaded earlier and sealed in the airlock. With a quick duck, the released bolts hit the polymorph which was emerging in full form behind them, exploding it.
The polymorph's demise instantly restores their altered personalities, and Kryten offers to commit suicide due to the guilt, and Cat and Rimmer are horrified as to what they are wearing. As they walk off, it is then revealed that a second polymorph has also arrived, and the second one turns into Lister, smiling.
The second polymorph is not seen again. In the remastered version, the second died of old age in Lister's clean underpants drawer.
- Craig Charles as Dave Lister
- Chris Barrie as Arnold Rimmer
- Danny John-Jules as Cat
- Robert Llewellyn as Kryten
- Frances Barber as Genny the Female Genetic Mutant who takes Cat's vanity
- Simon Gaffney as Young Rimmer
- Kalli Greenwood as Mrs. Rimmer
- Mike Agnew as Polymorph (voices)
Available on the Series III DVD:
- Extended dialogue in the "lunchtime with medical equipment" scene, and also a story about Lister's friend Olaf Petersen who spent a week in sick bay after trying Lister's Shami Kebab Diablo.
- The full, uncut growth of the polymorph to its real size. The initial transition was much slower, and more "toothy" and slimy, in the original edit.
- A lost Holly moment is followed by a fuller version of Cat's conversation with the Genny the mutant.
- A lost bit of dialogue expanding on Kryten's new guilt-free nature and Cat with no vanity. Kryten insults Cat, calling him an asshole, and Cat timidly agrees.
- Although the episode had a pre-credits warning about the episode's content, this was more of a plot device as the episode was broadcast past the 9:00 pm watershed.
- The Dwarfers would go on to encounter more polymorphs in episodes such as "Emohawk" and "Can of Worms". They would also encounter similar creatures and/or lifeforms with similar powers in episodes such as "Camille", "Back to Reality" and "Psirens".
- This episode reveals more about Rimmer's dysfunctional family, in that he was tormented by his brothers (Frank, John and Howard), and that his mother had no time for him (or more specifically she "despised idiots, no time for fools").
- This is the first appearance of Kryten's groinal attachment.
- This is the first appearance of bazookoids, weapons frequently used the Dwarfers.
- The shot in which the polymorph grows to gigantic size and sucks Lister's fear out of him reveals an aspect of Lister and Rimmer's sleeping quarters (in this case the Officer's Quarters) which is otherwise never evident on screen: that it apparently not only has a very high ceiling, but also sky-lighting.
- In the novel Better Than Life (the novels feature a different continuity to the television series), the polymorph was not killed by bazookoid blasts. In the novel, Talkie Toaster killed the polymorph by decapitating it with his bread tray.
- While they were discussing how to handle the polymorph, Lister shouted that "It's Clobberin' time," the catchphrase of the Thing of Marvel Comics' Fantastic Four.
- Rimmer also says "What about the Rimmer directive, which states never tangle with anything that's got more teeth than the entire Osmond Family." This a reference to the Osmond band.
- The remastered version of this episode adds several new digital effects shots. These include the polymorph moving through the Red Dwarf ventilation shafts at the beginning, after it chews through the hull. The remastered version of the episode also ties up a loose thread not concluded in the original version of the episode - the second polymorph seen at the end of the episode awaited to ambush Lister from his clean underpants drawer, but died of old age.
- Director Ed Bye drew inspiration for the visual design of this episode from watching Ridley Scott's classic 1979 horror film Alien prior to shooting, which features a similar-looking creature, Xenomorph. The polymorph's transformations also resemble the Alien's various transformations, from the early small worm to its large incarnation with a huge jaw holding an extendable emotion sucking tongue.
- The episode also had some of the show's most effects intensive scenes done yet. Animatronic versions of both the small and large polymorph creature versions were created. The small version was voiced by production manager Mike Agnew. The larger model, which was prone to tipping over, collapsed before the final shot. Blue screen was used to shoot the creature and added to existing footage of the crew. To achieve the polymorph morphing into all the different objects the traditional locked-off camera and jump-cut procedure was used.
- For the cargo bay scenes, a warehouse in Manchester was hired for the shooting, empty cardboard boxes were strategically stacked up and down the warehouse floor to give the illusion of a stocked cargo bay.
- During the filming of the Polymorph morphing into Lister's boxer shorts scene, the audience laughed so loud for so long that Chris Barrie had to wait several minutes until things had calmed down (the scene is now considered by many to be one of the funniest of the entire series). This also provided extra work in the editing room as the sequence required more work than usual to edit together a workable shot.
- The newly introduced Bazookoids provided more video effects as two heat-seeking laser bolts were fired and ended up chasing Cat. The heat-seekers were given sound effects borrowed from the lightsabers of Star Wars (but given unique sounds in the Red Dwarf Remastered version of the episode).
- According to Craig Charles on the DVD commentary, at least one viewer was upset enough by the acronym of Rimmer's suggested anti-polymorph organization (which happened to be the same as that of a female sexual organ) that she refused to watch Red Dwarf hereafter, citing her horror at a question about it being raised by her young daughter.
- In the early 1990s, Red Dwarf aired in Canada on YTV, a channel aimed at young viewers. While the network usually had to exercise some censorship in terms of language or other content, they evidently gave up trying to make "Polymorph" a family-friendly episode, and so it never aired on YTV.
- Rimmer: Well I can't say I'm totally shocked... You'll bonk anything, won't you, Lister?
- Lister (without his fear): I say lets get out there and twat it!
- Rimmer (without his anger): David. David. Do you have anything to bring to this forum? (While discussing how to beat the Polymorph)
Lister (without his fear): Yes, I have actually, Arnold. Why don't we go down to the ammunition stores, get the nuclear war-heads and strap one to my head?! I'll nut the smegger to oblivion!
Rimmer (without his anger): Right, well, th-th-that's very nice, David. Let's put that on the back-burner, shall we?
- Rimmer (without his anger): ...Um, I think we're all beginning to lose sight of the real issue here, which is: what are we going to call ourselves? And I think it comes down to a choice between "The League Against Salivating Monsters" or, my own personal preference, which is "the Commitee for the Liberation and Integration of Terrifying Organisms and their Rehabilitation Into Society". Um, one draw-back with that, the abbreviation is "Clitoris C.L.I.T.O.R.I.S."
- Mrs Rimmer: ...The things this boy can do with Alphabetti Spaghetti.
Rimmer: ALPHABETTI SPAGHETTI!?
- Kryten (without his guilt): It's got my guilt! I've lost the simple emotion which prevents my transgressing the mores, morays, and manners of civilized society!
Rimmer: Stop your blithering, Kryten! Come on. Grab the Cat and let's go!
Kryten (without his guilt): Oh, screw you, Hadron Head!
Plot Inconsistencies / Errors
- Rimmer suggests running away and the crew agree, yet in the next scene, they are going into the Cargo Deck in pursuit of the polymorph.
- The others may have resolved to pursue the polymorph, and Rimmer was simply too scared to be left alone.
- A possible explanation may be found in Red Dwarf novel Better Than Life when they go to the cargo deck to gather supplies to wait the polymorph out; it is possible that in the episode "Polymorph" they were in the Cargo Deck for similar reasons.
- This episode continues the trend in Series III of the writers ignoring the fact that Rimmer, being a hologram, should not be able to touch, or be touched, by any solid matter (indeed, this is a major element of several upcoming episodes). Yet the polymorph is able to touch Rimmer's forehead with its probe and suck the anger out of him, even though, being light generated by Holly, none of this emotion should actually reside where the hologram is. In the novel Better Than Life, it is more realistically stated that it ventured up into the Hologram Simulation Suite. In this case, it could have sucked the emotions out of Rimmer's light bee.
- It could have used it's plunger-like emotion sucker on Rimmer's light bee directly; a device which had not yet been introduced to the series. The light bee is Rimmer's only physical presence and which floats around inside his hologrammatical being. The light bee contains Rimmer's personality and memories, albeit digitally recreated, and so if the polymorph was able to tap into this it could potentially alter Rimmer similar to any biological.
- When the polymorph has turned into Mrs. Rimmer and is trying to make Rimmer angry, as she stands up from the table, you can see her bump into Rimmer. This should not be possible - Rimmer is a hologram, and therefore composed entirely of light; the polymorph, of course, is physical.
- The disguise could be a light field.