Sarah Jane is up to something. The kids get sick of her lying and sneaking around, so they follow her. Expecting something to do with aliens, they are shocked to see her on a date! Her boyfriend Peter Dalton soon pops the question. Clyde and Rani are naturally suspicious, and start investigating him. When they discover that his house is unlived in, Sarah Jane is unfazed. In fact, she's acting downright weird, waving off their suspicions and even deactivating Mr. Smith.

The day of the wedding arrives. Clyde smuggles K-9 into the chapel. Everything seems to be going smoothly... until the [[Series/DoctorWho Tenth Doctor]] crashes the wedding!!

Turns out it's all a ploy by the Trickster, who gave a dying Peter a second chance at life and even love, in order to get Sarah Jane to forget about fighting aliens. The ring is a brainwashing device, and Sarah Jane's "I do" would have sealed the deal. The Trickster traps the Doctor, Luke, Rani, and Clyde JustOneSecondOutOfSync with the rest of the universe, and Sarah Jane and Peter JustOneSecondOutOfSync with them.

Even under threat of being trapped forever, Sarah Jane won't give in. In a HeroicSacrifice, Peter calls off the deal. Cue TearJerker ending.

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!!Tropes

* AltarTheSpeed: Sarah Jane and Peter sure are in a rush to get married...
* BiggerOnTheInside: It's Clyde's turn to say it this time. Luke uses the term "dimensional trancendence" instead.
* BlatantLies: "Do not look at me. Everything is normal." -- K9
* {{Brainwashed}}: Sarah Jane, once again, in a nod to her tendency to get hypnotised in the classic series.
* CartwrightCurse: Poor Sarah Jane.
* ContinuityNod: Sarah Jane jokes about sending the Doctor's wedding invitation to Metebelis Three.
** Maria, Alan, and the Brigadier are also mentioned, though sadly can't make it.
* {{Crossover}}: This is the [[Recap/DoctorWhoS30E12TheStolenEarth second]] [[Recap/DoctorWhoS30E13JourneysEnd time]] ''SJA'' has directly crossed over with its parent show. (At least when judged by airdate; the [[Recap/DoctorWhoS30E17E18TheEndOfTime third crossover]] was filmed before this one, but aired after it.)
* DatePeepers: Luke, Rani, and Clyde.
* DeadpanSnarker[=/=]VitriolicBestBuds: Mr Smith and K9, as always, show shades of this.
* DealWithTheDevil: Peter does this, though in fairness, he thought it was a BargainWithHeaven.
* DecemberDecemberRomance: Both Peter and Sarah Jane are getting on in years.
* FourthDateMarriage: Justified, for once.
* GenreBlind: Apparently, Peter didn't think anything of giving Sarah Jane a ring that ''controlled her mind.'' And the fact that "the angel" gave it to him doesn't seem to have clued him in at all.
* GenreSavvy: When Sarah Jane starts keeping secrets and going off on her own, the kids correctly suspect that something's going on, though they don't realize what. Clyde also has the savviness to bring K9 to the wedding.
* GoldDigger: Rani and Clyde suspect that Peter is one.
* AGoodNameForARockBand: The Pantheon of Discord, according to Clyde. The Doctor agrees.
* HamToHamCombat: Ten has ''an enormous ability to show off''... and the Trickster is an enormous ham. The two end up meeting.
* HeroicSacrifice: Peter, who gives the Trickster a brief TheReasonYouSuckSpeech.
* IncomingHam: The Trickster, as usual. ''' ''DOCTOR!'' '''
* JustOneSecondOutOfSync
* LameExcuse: Even K9 thinks Sarah Jane's excuses are pathetic.
* LargeHam: The Tenth Doctor turns up. Need we say more?
* MindControlDevice: Sarah Jane's engagement ring. When things get just ''too'' weird, though, she has the willpower to take it off.
* PaletteSwap: The Trickster invokes this, appearing in white instead of black to Peter.
* ParentWithNewParamour: Unusually for this trope, Luke is [[ShipperOnDeck enthusiastic about Sarah Jane's new beau,]] forbidding Clyde and Rani from ruining things.
* SheCleansUpNicely: In a completely non-romantic example, this is Luke's response to Rani and Sarah Jane all dolled up for the wedding.
* SpeakNowOrForeverHoldYourPeace: Obviously. Done by the Doctor himself, of all party crashers.
* TheMasqueradeWillKillYourDatingLife: Narrowly averted. Sarah Jane receives a package containing an alien life form at the same time Peter shows up at her house. Fortunately, Rani and Clyde are there to cover for her.
* WeddingDeadline: And the fate of Earth hangs in the balance.

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