[[Creator/PeterDavison The Fifth Doctor]] is investigating a time leak at a lab. He's interrupted by the cyborg lead scientist's cyborg brother, Colonel Ulrik, who barges in with an army of Daleks. They're after something very dangerous inside the main vault.

[[Creator/PaulMcGann The Eighth Doctor]]'s TARDIS lands him in the same lab, and after a moment of confusion, he remembers visiting the lab about a millenium before (when he was all blond and crickety and "terribly polite") and almost being killed by Daleks. Since he also remembers a conversation he had with an anonymous Time Lord, he deduces that he'll now have to go pretend to be said anonymous Time Lord so as not to screw up the timeline (after all, if he'd revealed his identity at that point, he ''wouldn't'' have remembered it). Through a beaten-up intercom and some fumbling to obscure his voice, he manages to convey to Five that they need to activate a time loop between their [=TARDISes=].

[[Creator/SylvesterMcCoy The Seventh Doctor]] is visiting a friend in 1854, [[HistoricalDomainCharacter Professor Michael Faraday]], who has recently come into the possession of a Special Weapons Dalek. Ulrik also ends up in Faraday's laboratory and, after being extremely confused for a while, starts to go for the Dalek. The Seventh Doctor remembers having faced Ulrik twice before and manages to send him, and the Special Weapons Dalek, back in time to the war Ulrik's grandfather fought and died in.

Ulrik's training never prepared him for historical war, and terrified, he hides in the manor that he knows was also the place where his grandfather was killed in this war. He's quickly captured and tortured for months by Daleks, who don't recognise his cyborg design, since it hasn't been invented yet. They also don't recognise the Special Weapons Dalek, although it insists that the others have to obey. [[Creator/ColinBaker The Sixth Doctor]], who knew Ulrik would appear here from remembering doing the adventure as the Fifth, gets Ulrik out of his cell. It's discovered that the cyborg race reverse-engineered their technology from the Special Weapons Dalek... and built their own Dalek-shaped tanks, modifying their own bodies to work together with regular parts of Dalek shells and exert control over them. The future Daleks took out this part of the design as a reaction. The cyborgs also captured Ulrik's grandfather, whom Ulrik believed died a cowardly death in the war. Instead, as it turns out, they fused Ulrik's grandfather with the Special Weapons Dalek, who will one day end up in the the cyborgs' laboratory vault.

The four Doctors and Ulrik eventually end up back at said vault -- meeting the younger Ulrik -- and release Ulrik's grandfather, who is ''almost'' able to save the day by accepting Ulrik's orders. But the older Ulrik dies, and the younger, who is extremely bewildered, gets sucked into the time loop together with the Special Weapons Dalek, to end up in 1854.

The Doctors banter for a bit, realise that only Eight will remember this part, and get sent back to their own timelines.

!Tropes:
* AlienSky: The Sixth Doctor describes one to Ulrik.
* AnachronicOrder: The Eighth Doctor mentions having been to the Battle of Penjorica before we get to see his Sixth incarnation go through it.
* BlahBlahBlah: The Eighth Doctor cuts the Fifth off with a "Yadda yadda yadda" because he's already gone through the scenario once.
* CallBack: There's a [[Recap/DoctorWhoS25E1RemembranceOfTheDaleks Special Weapons Dalek]] on the station.
** When the Eighth Doctor arrives he thinks he's somewhere else, and that they've redecorated. And [[Recap/DoctorWho20thASTheFiveDoctors promptly declares]] [[RunningGag his dislike for it]].
** Professor Faraday thinks the Daleks would not be able to [[Recap/DoctorWhoS22E6RevelationOfTheDaleks ascend stairs]]. He's wrong, of course.
** The Daleks employ a [[Recap/DoctorWhoS2E2TheDalekInvasionOfEarth Roboman]].
** In there is a [[Recap/DoctorWhoS21E4ResurrectionOfTheDaleks Time Corridor]] in Professor Faraday's laboratory.
* ChekhovsGunman: The Roboman.
* {{Cliffhanger}}: Each Doctor's segment ends with him in front of a Dalek, ready to exterminate him.
* CodeName: The Eighth Doctor says that "The Doctor" is one, explaining why both the Fifth and the Eighth call themselves "The Doctor" to Kalinda.
* {{Cyborg}}: Kalinda and Ulrik are Jariden, so called "Bio-mechanoids".
* TheFarmerAndTheViper: The Eighth Doctor mentions a deal with the Daleks for your "own personal safety" is like this. And some people still go through it. With the expected results.
* FishOutOfTemporalWater: Ulrik is sent back to London in 1854 through a Temporal Whirlwind.
* GivingRadioToTheRomans: The Special Weapons Dalek (And Dalek Prime) end up earlier in the Dalek history, and the then-Daleks and Jariden use that technology to upgrade themselves. [[StableTimeloop That Ulrik already possesses]].
* HaveWeMetYet: The Seventh Doctor meets Ulrik before his Sixth incarnation does, and Ulrik meets the Eighth before he meets any of them.
* HistoricalDomainCharacter: [[http://en.wikipedia.org/wiki/Michael_Faraday Professor Faraday]].
* IndyPloy: The Seventh Doctor manages to use 19th Century science to hinder two Daleks.
* MindScrew
* MoodWhiplash: We go from a SpaceStation being invaded by Daleks and the Fifth and Eighth Doctors facing eminent death, to ... a calm and relaxed scientific presentation in 1854 with harpsichord music.
* TheProfessor: [[http://en.wikipedia.org/wiki/Michael_Faraday Professor Faraday]].
* RippleProofMemory: The later Doctors remember everything their Fifth Incarnation went through. Though they don't remember their meeting in the TARDIS at the end; only the Eighth does.
* RunningGag: Every time a Doctor enters a later Doctor's TARDIS (in the series as a whole) the younger one comments on not liking it.
* SpecialEditionTitle: The opening theme is used from [[Recap/DoctorWhoS1E1AnUnearthlyChild An Unearthly Child]].
* SpeakInUnison: The Four Doctors, when in the same room, say the same sentence
--> '''Doctors''': We Time-Lords have too much to remember as it is.
* StableTimeLoop:
** The Eighth Doctor tries to feed bits to the Fifth without giving away who he is, just as he remembers.
** Ulrik's ''existence'' is one.
* TakeThatMe: Six asks Eight what on earth he's done to the TARDIS interior. Eight quips that Six should ''hardly'' comment on ''taste'' [[IWasQuiteAFashionVictim of all things]].
* TimeAbyss: Ulrik (the elder) is permanently looped in the Doctor's life.
** FateWorseThanDeath
* TimeyWimeyBall: Ohh boy.[[note]]Ulrik gets knocked out by his future self. This causes the Daleks to exterminate the future incarnation, leaving the younger alive. The younger Ulrik gets caught in a Temporal Whirlwind caused by the Fifth Doctor. He ends up in 1854 in London with Professor Faraday and the Seventh Doctor, stumbling through a timecorridor. The Seventh Doctor launches him, the Special Weapons Dalek and Dalek Prime into the Perojican war, which is in 1854's future, but in the original starting point's past. There Ulrik gets captured by Daleks, imprisoned where the Sixth Doctor finds him, and sends him hurling into the future, where he ends up on the ship, where he learns his sister is with the Eigth Doctor who manipulates the Fifth Doctor into creating a Temporal whirlwind. Ulrik then proceeds to knock out his younger self, causing the Daleks to exterminate him instead of his younger self, causing his younger self to get caught up in a Temporal Whirlwind...[[/note]]
* TrojanPrisoner: The Dalek Prime allows himself be captured in order to enter Dalek control at the battle of Pejorica.
* WetwareCPU: Ulrik describes the Jariden as wetware.
* YouAlreadyChangedThePast: Ulrik already having an upgraded (with reverse engineered Dalek technology) body compared to the Jaridens at the battle of Pejorica, says to the Doctor that the Jaridens would find the Special Weapons Dalek and reverse engineer it.