Without even an opening title sequence to kick things off, this sequence features an impressive (for the time) CGI shot of the TARDIS randomly flying around as it gets zapped with lasers. Why it's zapped with lasers, what's going on, who's doing what, that's unimportantnote the TARDIS is being zapped and forced to land on an exotic alien planet as a day-glo lizard guy watches. The Rani steps in and gloats while one of her henchmen rolls over someone in the Sixth Doctor's outfit, revealing a guy in a wig who then regenerates into the Seventh Doctor right before our eyes.note
The title sequence is now finally shown, the first one to ever use CGI in the series, equally as impressive for its time as the opening scene of the teaser. Not so much can be said on the theme arrangement accompanying it, though, being an unusual departure from the instrumental tracks composed on the show, but the synthesizer beat's still pretty nifty. And trust us- it will grow on you. It's one of the first compositions by newcomer Keff McCullough, who will be providing the soundtracks for the remainder of the classic era, and lathering every story hereafter in poppy late 80's synth.note
Once it ends, the Rani then takes the Doctor off to her secret laboratory, where he wakes up and deduces that she's going to do something horrible with a nearby asteroid made up of Strange Matter. Before he can do anything else, one of her bat-like mooks, the Tetraps knocks him out again, and she doses him with amnesia juice, while leaving the companion Mel back in the TARDIS to stumble around the exotic alien landscape with that day-glo lizard we saw earlier. The Doctor awakens to see the Rani disguising herself as Mel and acting like Mel for... um... we're never really told why. Maybe the Rani simply wanted to be the Doctor's companion for a while.
The Doctor is very miffed to have regenerated, and even more miffed by what he thinks is regular old post-regenerative amnesia. He refuses to do any work until his mind starts working again and goes off to pick a new outfit instead, finally freeing himself— and the viewers— from two seasons of dressing up as animated clown vomit in the process. The Rani, whose Mel disguise is working rather well, decides to go enslave some more lizardmen.
Mel sneaks into the Rani's evil base of operations (after having been Trapped by Mountain Lions for a couple of hours) and the Doctor, still amnesiac, thinks that she must be the Rani. They quickly sort out the confusion by checking each other's number of pulses, and after a sweet Headbutt of Love, they head off together to stop the Rani's evil plan.
Eventually, the Rani's diabolical scheme is revealed: she's been kidnapping the smartest people throughout space and time in order to create a gigantic artificial brain. By blowing up the Strange Matter asteroid, she will expose the brain to radiation that will cause it to grow bigger and bigger until it engulfs the entire planet, and give it the power to control time anywhere in the universe. Yep. Since the Rani really loves dinosaurs, she's going to retroactively replace Earth's population with them. And possibly some other stuff. Evil stuff. However, her plan involves hooking the Doctor up to the giant brain together with the likes of Einstein and Pasteur, who of course all immediately proceed to not listen to the Rani. The Doctor rescues the lizardmen, straps their bombs to the giant brain instead, and taunts the Rani into activating said bombs. He drops the geniuses off back home (promising Einstein he'll show him how the TARDIS works later. He'd later have trouble with this.) and runs off for more adventures with Mel in the TARDIS. As for the Rani, she's left (literally) hanging with the Tetraps, who are a little peeved that she intended to let them get fried by the asteroid explosion, as she vows her revenge. She's still not very good at her job.
It's worth noting that this story was originally intended for Colin Baker's 6th Doctor by Pip and Jane Baker (old hands at writing for him by this point), but was sent through the re-write cycles once Colin was fired. It's notable for the final appearance of the Rani in the series (not counting Doctor Who 30th AS "Dimensions in Time"), as well as the first appearance of the 7th Doctor.
- Airplane Arms: The Lakertyans run like this, though with their arms very close to their bodies. Apparently the intention was to make their species and culture more alien: it worked very well.
- Amnesiac Hero: The Seventh Doctor spends most of his first story as a dupe of the Rani - though this was the fault of her amnesia serum, not random happenstance.
- Apathetic Citizens: The Lakertyans for the most part don't seem particularly bothered about what happens to them.
- Bat Out of Hell: The Rani's Tetrap mooks.
- BBC Quarry: About 2/3rds of the episode are spent meandering over one.
- Bee Bee Gun: Those bug spheres.
- Brain Monster: The Rani grows a giant brain linked to the minds of every genius in the arcade in an attempt to collect the genius of the greatest scientific minds in the universe.
- The Cast Showoff: Invoked. McCoy was good at doing pratfalls and mugging. And playing the spoons.
- Characterization Marches On: McCoy's performance as the Doctor is very cuddly and goofy, and he's not yet become the manipulative mastermind that Seven would later turn out to be. However, this is his regeneration story, and he spends half of it drugged by the Rani. Also, he wears braces with his costume for the first and only time.
- Conspicuous CGI: The TARDIS being attacked and forced to land; the title sequence; the bubble trap.
- Continuity Cavalcade: While picking a new dress style, the Doctor tries on the Second Doctor's furry coat, the Third Doctor's ruffles, the Fourth Doctor's entire wardrobe, and the Fifth Doctor's cricket outfit (shin protectors and all).
- Costume-Test Montage: After spending most of the story in his predecessor's costume, the Seventh Doctor tries out costumes of the Second, Third, Fourth and Fifth Doctors before settling on his new costume.
- Death by Falling Over: Poor Six. Well, it's what we are led to believe from what plays out onscreen. The opening seemed more like a reprise from another story for the longest time. Turns out it was.
- Death Trap: One of the most ingenious the series has had so far. It's a tripwire that, when triggered, envelops the target in a force-field bubble, which then flies off until it hits something and explodes.
- The Dog Bites Back: Urak at the end.
- Dropped a Bridge on Him: The not-so-pretty fate of the Sixth Doctor here. The Expanded Universe gives other explanations; either Seven, despite not being born yet caused the death so he could become Time's Champion, or the Doctor was already weakened from using up a lot of his energy to save creation. Finally averted with "The Sixth Doctor: The Last Adventure", the True Ending to his Doctor's life.
- Enhanced on DVD: The DVD re-release features the option to digitally insert Colin Baker into the opening regeneration scene, with his face morphing into that of his successor's in a golden glow.
- Establishing Character Moment: An arguably unintentional example, given that the character wouldn't really be taken in this direction until the following season, but the very first thing the Seventh Doctor does upon regaining consciousness after regenerating is start to organise his schedule ("That was a nice nap; now, down to business! I'm a bit worried about the temporal flicker in Sector Seventeen..."). Later series and the Doctor Who Expanded Universe would have the Seventh Doctor act as The Chessmaster who intentionally sought out particular conflicts rather than just happening to stumble across them as previously, and made a point of devising a plan for how to deal with the situation prior to arriving.
- Evil Laugh: The Rani plays it straight.
- Evolving Credits: A new Doctor means a new intro, the final one for the Classic Series and the only one made entirely from CGI.
- Fake Shemp: Colin Baker was offered the chance to appear as the Doctor in this story; as originally planned, the Doctor would have stayed behind to make sure the strike on the Rani's base was successful and been mortally wounded in the explosion. However, Baker refused to return for anything less than a full series,note and the script was rewritten so the Doctor regenerates at the start of the story. Sylvester McCoy had to wear a wig and the regeneration was done by obscuring his face with some Quantel blurring effects. Not good enough for you? Apparently, someone else with a computer agreed. The DVD release has an easter egg with a splendid CGI edit of Colin's face.
- Filming for Easy Dub: When Colin Baker was dropped from the series, Sylvester McCoy was forced to don a blonde curly wig and lie face down, before turning over just as the regeneration effects conveniently obscure his facial features with a bright glowing light. The truth is it doesn't even work: if you look closely you can see that it is McCoy under the glowy effect, and you can see the line between the wig and his head.
- For the Evulz: The only explanation as to why the Rani would disguise herself as Mel. Averted later on in the story, when the Doctor says that blowing up the Strange Matter asteroid would obliterate all life in that part of the galaxy, but immediately dismisses the possibility of the Rani's motive being mass-slaughter for the sake of it, saying that it doesn't fit her MO.
- Hand Gagging: A Tetrap does this to Mel towards the end of episode 3.
- Headbutt of Love: The Doctor and Mel.
- Historical Domain Character: The kidnapped geniuses, if they count as characters. None of them have lines.
- I Was Quite a Fashion Victim: When the Doctor sheds his predecessor's... interesting... clothing, he remarks "I'm glad to see I've returned to a sense of haute couture".
- Let's You and Him Fight: This happens between the Doctor and Mel — she didn't realise he was the Doctor because she hadn't seen him since the regeneration, and the last time he'd seen "her" it had been the Rani in disguise.
- Meaningful Name: The Lakertyans were named after the Latin word Lacertian (lizard-like).
- Mixed Metaphor: Out of sorts from regeneration, and moreso than usual because of the Rani's tampering, the newly-minted Seven is always doing this. Knowing Seven it could be Obfuscating Stupidity, but his characterization wouldn't go in that direction for a while, and the Earth phrases he's using aren't anything anyone he's talking to should ever have heard in the first place.
- Multipurpose Tongue: The bat-like Tetraps have weaponized tongues tipped with knockout venom.
- The Nth Doctor: Sylvester McCoy makes his debut as the Doctor.
- Nothing Can Stop Me Now: The Rani's notorious "I HAVE THE LOYHARGIL! NOTHING CAN STOP ME NOW!".
- The Noun and the Noun
- Prisoner Exchange: The Rani for Mel.
- The Quisling: Beyus.
- Really 700 Years Old: The Doctor notes that he and the Rani are the same age, 953 years old. Either "rule one: the Doctor lies" applies, or he's forgotten how old he actually is.
- Rearrange the Song: Keff McCullough handles the soundtrack from now on, meaning layers of synths.
- Recycled Premise: The concept of creating a weapon by collecting the minds of all the great thinkers, including the Doctor's, was also used in "Shada". Both stories involve the Doctor using his stolen consciousness to counteract the weapon.
- Resurrection Sickness: The Doctor loses his memory for a while, having been drugged by the Rani.
- Senseless Sacrifice: Is there any actual reason why Beyus insists on staying with the brain to get blown up?note
- Sequel Episode: To "The Mark of the Rani".
- Significant Anagram:
- LOYHARGIL = HOLY GRAIL. ("Holy grail," in this case, is a metaphor.)
- Tetrap is an anagram of "pet rat".
- Stealth Pun/Visual Pun: The Seventh Doctor wears a Tartan scarf. Seven has a Scottish accent. And of course, Sylvester McCoy is Scottish.
- The Teaser: The story opens with the Rani attacking the TARDIS and the regeneration; the third of four examples of this in the classic era, and the first to be specially filmed rather than using archive footage.
- Techno Babble: The Rani's description of how she intends to transform the planet and her giant brain into a time manipulating weapon.
- Wig, Dress, Accent: The Rani is able to impersonate Mel and fool the Doctor with nothing more than a wig! Granted, the Doctor was suffering from regeneration sickness at the time. In general, the Rani just likes disguises.
- With Catlike Tread: A monster spends an episode and a half stalking the heroes, then finally gets the drop on them, pops up from behind a rock a foot away, and roars triumphantly for ten seconds.
- Xenafication: Mel shows combat skills she never does before or later, in the scene where she thinks the new Doctor is a bad guy.
- You Have Outlived Your Usefulness: The Rani indirectly pulls this on the Tetraps, by telling the Doctor and Mel that she's going to leave them on the planet to die when it's transformed into a time manipulator. Unfortunately for her, the lead Tetrap overhears this, and does not take politely to it.