Operation: Kill Katherine Dead is in full effect in this Very Special Halloween episode of “The Vampire Diaries,” which is also throws in a little Mission: Impossible and touch of “Jerry Springer” for good measure. Who will die? Who will NOT die? And who’s the dude in the creepy clown mask?

Katherine’s arc appears to come to a close – at least for now – as Damon and Stefan’s task force sets an ambush at the annual Mystic Falls Masquerade Ball. Jumping into action from the get-go, show runners Julie Plec and Kevin Williamson take the scripting reins, deftly shifting momentum around so that everyone gets some action – even dour Bonnie, whose love life might finally be looking up after tonight.

The episode’s best trick, alas, turned out to be a one-off gimmick. (How are Elena and Katherine connected, if not by a single magical spell?) Tonight also demonstrated how much we’d miss the sensual, smart, badass Katherine if she weren’t around anymore to make wanton passes at Mystic Falls’ most eligible bachelors and slyly show us that she knows that we can tell her and Elena apart.

So bid farewell to Katherine (at least, for now) and get ready for more dowdy, whiny Elena as Katherine’s arc closes and another one begins. At least those annoying Mystic Falls High floozies are gone. Bring on the next underboss!

[Full recap of Thursday's (Oct. 28) "The Vampire Diaries," titled "Masquerade," after the break…]

Pow wow at the Salvatore mansion, where Carolyn reports a spooky run in with Katherine in the Mystic Grill ladies’ room. Katherine has a message for Damon and Stefan: She wants the moonstone. TONIGHT! At the Masquerade Ball! Or else!

The bros come to the same decision: Katherine must die! (Does the “TVD” title card always drip blood, or am I only noticing it on tonight’s already off-to-the-races very special Halloween week episode?)

For some reason Matt is helping Elena and Jeremy bring Aunt Jenna home from the hospital. Jenna, hilariously, still thinks she walked into that knife. Elena’s all for playing it safe to avoid Katherine’s wrath, but Jeremy’s still in Young Indiana Jones mode and wants to spring into action.

Elsewhere, Katherine’s compelled herself a nice old lady sugar mama named Ms. Flowers. As Katherine the clothes horse admires some recent purchases, a new character sneaks up behind her. She’s African-American and a lady, which can only mean one thing: She’s a witch! They’re totally home girls. Witch lady’s gonna be Katherine’s date to the ball.

Stefan and Damon call on their own witch, Bonnie, to help hatch Operation: Kill Katherine. The whole gang’s here, mostly: There’s Caroline, Jeremy, and Alaric, who outfits everyone with their own custom-fitted vampire-slaying weapons. Only Elena is absent. But then, not everything’s about Elena all the time. Someone tell that to Elena.

Except that, for Katherine tonight, it is all about Elena – or rather, impersonating Elena -- which is what the Katherine plans to do at the Ball. BY STRAIGHTENING HER HAIR! Weeks after we at home realized the key difference between the curly-haired Katherine and her “dull as dishwater” straight-haired doppelganger, Katherine’s pulling out all the stops to make sure she passes for Elena. If you’re playing along at home, this now means that Nina Dobrev will be playing A) Elena, B) Katherine, and C) Katherine looking exactly like Elena tonight.  Every week a new acting challenge.

Katherine’s hot witch friend is Lucy, and she’s going to help her get the moonstone back. And then Katherine would like Lucy to break the curse, whatever that means. Meanwhile, Stefan wants Bonnie to use her powers to isolate Katherine like she and Grams did with the tomb vamps. Bonnie reluctantly agrees. Alaric is tasked with guarding Elena. Caroline wants revenge. Jeremy wants some action! So many plans going into motion, how will they all intersect?

Back at the Gilbert house, Matt’s acting way weird. When Elena tells him she plans on staying home from the Masquerade Ball, Matt (who’s under Katherine’s brain-slave spell) suddenly has to leave. To do something.

All of a sudden we cut to the Lockwood Mansion, because do you know what time it is? It’s Masquerade Ball time! The writers this week aren’t messing around. Mayoress Lockwood and Tyler do some mother-son chitchatting as the party begins, musing over the recently departed Uncle Mason. “I don’t know what this party had to do with helping the homeless,” Mayoress Lockwood ponders, before kind of complimenting her son by telling him that he and his dad were both jerkwads. Ah, Lockwood family bonding.

So here’s how we can tell that straight-haired Katherine is still Katherine during tonight’s Masquerade Ball: She sashays like she’s walking through a music video and has a sexy witch by her side. Katherine runs into Matt and gets hot and bothered over his scrumptiousness before getting back to the plan: Matt is to pick a fight with Tyler tonight at the party until Tyler snaps and kills him, thus triggering his transformation. Nina Dobrev as Katherine = hilarious.

The Brothers Salvatore chitchat while surveying the party scene; in their man-masks they resemble sparkly Kato-styled vigilante heroes. Stefan wonders if Damon will be able to come through and kill Katherine after all.

Over in his father’s off-limits study, Tyler’s hosting another underage drinking party – this time with Matt, Amy, and her friend who fell down the stairs and almost died that one time. Matt plies the group with booze, which is the first time Zach Roerig has gotten to play anything remotely resembling real life teenage fun all series!

Okay, everyone at this Masquerade Ball either looks like Kato or the orgy people from “Eyes Wide Shut.” Including Bonnie and Jeremy, who’ve paired off and now hole up in an empty upstairs room. Jeremy tells Bonnie it’s awesome that she’s a witch; Bonnie tells him she hates it because everyone in her line of work dies. They totally have a moment, in which Steven R. McQueen flexes his jaw muscle like he’s James Bond. It’s hot.

Back at home, dowdy Elena is hanging with the parental units – the recovering Aunt Jenna and her squire/secret babysitter Alaric. Stupid Elena pouts and wonders why all of her friends and her brother are at the party without her. Shut up Elena, we think to ourselves. Enjoy your safety and comfort and plain pink sweater.

After prepping the attack room, Bonnie and Jeremy rejoin the party – but Bonnie feels a strange force. She taps Lucy on the shoulder and wonders if they know each other, but Lucy says she’s just someone’s plus 1. Bonnie shrugs it off.

Stefan spies Katherine across the crowded lawn as a sultry Hot Topic-y cover version of Tears for Fears’ “Head Over Heels” plays  with zero subtlety in the background. Katherine extorts a slow dance from Stefan under threat of killing a random partygoer and demands the moonstone. Their tense conversation is interrupted by Stupid Amy, who unwittingly becomes Katherine’s fleshy human tool; Katherine punches her in the spine to paralyze her … and then does it again, killing her dead to show Stefan that she ain’t messing around! Time of death: First 20 minutes. Glorious!

Stupid Elena sneaks out of the house because it’s KILLING HER that everyone she knows is at the Lockwood party and she’s not there. Ugh. Over at the party, Stefan freaks out about Dead Stupid Amy. He thinks the risk of collateral damage is too high and that they should just call the whole thing off. Damon bro-talks some sense into Stefan by staring with purpose into his eyes and promising that he’s got his back.

Jeremy and Bonnie chitchat as they wait for Operation: Kill Katherine to begin. More flirting. She declines a dance. And then comes the call to arms – rather, the text message to arms, because as we learned last week, mobile cellular telephones are all the rage with teenagers these days!

Lucy catches up with Katherine, who’s sashaying sexily through the party killing time. Lucy worries that Bonnie spotting her means her involvement will be known, when she wanted to do Katherine a solid on the DL. They’re interrupted by Jeremy, who innocently cuts in to talk to “Elena.” Jeremy’s amateur secret agent skills have improved, because once they’re alone, Jeremy reveals his role in the Operation. He delivers a message to Katherine from Damon and Stefan, telling her to meet the brothers out by the lake for the switch. As Jeremy walks away into the bushes, Elena pulls him aside to ask just what the heck is going on.

Caroline, meanwhile, spies Matt drunkenly cavorting with Dead Stupid Amy’s friend Sarah. They lock eyes across the room and exchange sweet meaningful glances. Matt walks away as a plaintive song in the background wails about people changing. Caroline gets – you guessed it! – a TEXT MESSAGE from Jeremy telling her it’s her turn. She heads for a restroom, where once again Katherine corners her. They’ve got to stop meeting like this. Weirdest recurring theme ever.

Katherine wants to know what the Salvatores are really planning. She chokes Caroline out until Caroline tells her that the boys are trying to kill her, Bonnie has the moonstone, and that she’s downstairs at the party. Katherine forces a whimpering Caroline to escort her to the Salvatore Gang secret war room upstairs … but it’s a trap! Caroline beams with pride as Katherine finds herself magically imprisoned in Mayoress Lockwood’s well-appointed sitting room, and then leaves as Stefan and Damon appear with stakes.

Back in the bushes, Jeremy and Bonnie have filled Elena in on the very same developments. She thinks they’re crazy for trying to go after Katherine. They’re about to find out Elena’s right … because as Damon fires a stake into Katherine’s back upstairs in the Lockwood mansion, the same spot begins to bleed through Elena’s clothes down in the garden!

After the longest commercial break ever, we return. Upstairs, the Brothers Salvatore continue to stab away at Katherine, not knowing that their beloved Elena is being magically stabbed along with her outside. Bonnie figures out what’s going on and sends Jeremy racing to the house to stop the double massacre, where the 2-on-1 assassination has turned into a fairly evenly matched 2-on-1 fight. That Katherine must have worked out a lot in her century-plus of downtime. Jeremy gets to the room just in time to stop Damon from dealing a death stake to Katherine/Elena.

Katherine explains to the stunned threesome that she’s also got a witch on her side – a really good witch. She takes a stake and drives it into her own hand just to cause Elena more pain, and threatens to do more harm to herself/Elena if she doesn’t get the moonstone.

Bonnie figures out that Katherine’s witch is the woman she saw inside at the party and races off to challenge her to a witch-battle. Jeremy tends to his wounded sister and implores Elena to take his magical healing ring.

Back upstairs, the Brothers Salvatore are stuck with their ex. Awkward! It’s like a vampire episode of “Jerry Springer;” Katherine tries to turn Damon and Stefan against each other by manipulating their shared love for Elena. Katherine reveals that Elena feels whatever she feels – even desire for Damon. Talk turns to werewolves as Stefan wonders what Katherine wanted to use Mason Lockwood for in the first place.

Which brings us to our other wolf-in-training. Tyler’s getting sloshed with Sarah and Matt, who begins provoking Tyler per Katherine’s orders. Matt insults Tyler’s dead daddy and begins beating him over Tyler’s protests, which turns into an all-out brawl in Mayor Lockwood’s study. Caroline overhears the commotion with her vampire hearing and breaks up the fight by knocking Matt out with her super strength, which takes Tyler by surprise. But wait, why’s Sarh inching toward Tyler with a penknife?

Sarah begins talking to herself, revealing that she’s been compelled by Katherine into being Tyler’s back-up plan: If Matt fails, she must finish the job and make Tyler change into a wolf. Sarah lunges at Tyler and stabs him in the shoulder, and he pushes her back in self-defense – all the way back towards Daddy Lockwood’s desk, where Sarah hits her head. Caroline kneels to check for a pulse, but Tyler’s face tells us Sarah’s dead as he begins to convulse and his eyes turn black. AND we’ve got 20 more minutes to go!

Upstairs, Stefan figures out that Katherine needs the moonstone because she traded it away long ago to George Lockwood, which prompts a Scooby-esque “And it would have worked, too, if it wasn’t for you pesky kids” response from Katherine. Stefan surmises that Katherine needs it back because it wasn’t hers to give – and that when she faked her death in 1864 she was running from someone.

Katherine throws Stefan off by revealing that she’s checked in on him from time to time; she spied on him at a Bon Jovi concert with Lexi back in the ‘80s. She mouths “I love you” with her back turned so that Damon can’t see.

Bonnie finds Lucy – or rather, Lucy finds her. They have witchy words; Bonnie demands Lucy remove the binding spell that’s connecting Elena to Katherine and shames her for helping Katherine in the first place. Here we find one of the more delicious conversations of the episode: Bonnie threatens the older, taller, and more powerful Lucy with the tenacity of a terrier until Lucy admits that she’s indebted to Katherine for once saving her life. Bonnie grabs Lucy’s arm, which allows Lucy to sense that Bonnie is the one who has the moonstone. They grasp forearms and the overhead lights flicker with magic as Lucy tries to magically compel Bonnie to hand over the stone.

Damon feeds Katherine some vervain-laced scotch, threatening to stake her once the spell’s been lifted. Katherine, meanwhile, brushes all of this aggression off with a sultry smile; she’s like a cat in heat tonight, eyeballing every hunk of man meat on the show. They’re interrupted by Lucy, who strolls in with the moonstone in hand. The room imprisonment spell has been broken and once Lucy gives Katherine the stone, they’re done professionally.

Katherine agrees, and Lucy drops the moonstone in Katherine’s outstretched hand over Damon’s protests. Katherine struggles under some witchy power as Lucy reveals that she’s lifted the spell that binds Elena to Katherine and poisoned the moonstone, on account of Katherine neglecting to tell her that another witch would be involved in the night’s shenanigans. Lucy apologizes and makes a badass exit as Katherine chokes on the floor. Is that relief or distress on the surprised Salvatore mugs?

Caroline feeds a PR-friendly cover story to Mayoress Lockwood explaining why there’s a dead teenager in her husband’s study. Caroline and Tyler are left alone to exchange real talk about what just went down, and Caroline reveals that she knows what Tyler has become.

Outside, Bonnie catches up to say goodbye to Lucy. She wonders how she knew she could trust Lucy when she gave her the stone, and Lucy reveals that she’s Grams’s niece’s second cousin (or something) and therefore a Bennett. Lucy thanks Bonnie for snapping her out of her cycle of abusive relationships with vampires who are no good for her – this IS a very special supernatural episode of Jerry Springer! –and tells Bonnie she needs to stay in the game to do the most good. Jeremy saunters up  to offer Bonnie a ride home and Bonnie’s all, “When did YOU grow up, Jeremy Gilbert?” They walk off into a new, promising romantic story arc.

Speaking of romance, Stefan finds Elena standing by herself in the Lockwood garden by the lake – exactly where someone fearful of evil vampires and supernatural creatures should NOT be standing by herself in the middle of the night, but whatevs. Stefan tells Elena that Katherine’s “gone” – and I’m confused: Did Katherine die ten minutes ago and I didn’t realize it? Lame sauce way to let Katherine go, writers.  

But even with the threat of Katherine (allegedly) gone, Elena’s fearful of jumping back into her relationship with Stefan. Why, I don’t really understand. Something about needing to make sure the people she loves are safe.

But wait! Of course Katherine didn’t die; she’s just stuck in the tomb, where she was always thought to have dessicated away. Damon’s brought here there for some poetic justice, because “death would have been too kind.” That, and it would have left “The Vampire Diaries” with nothing much to do. Katherine pleads with Damon that he still needs her because there’s something scarier than her out there and it’ll come after Elena. As Damon closes the tomb door on Katherine, her last line hangs in the air: “She’s the doppelganger, she needs to be protected.” WHAT’S IT ALL MEAN??

Elena walks solo toward her car, because remember? She totally broke things off with Stefan and left him to mope by the lake. Which is too bad, because a mysterious figure wearing a sparkly clown mask comes up from behind and grabs Elena, muffling her screams.

Next week: Elena’s been kidnapped, so the Salvatore boys are goin’ on a road trip!