It always comes back to Katherine, doesn’t it? As Stefan and Elena secretly work against Damon to find the Grimoire that can free Katherine, we flash back to the past to find out what exactly Stefan did to make Damon hate him for all of eternity. (Hint: it involves Katherine, their love triangle, and Kelly Hu.)

[Full recap of Thursday's (Feb. 4) "The Vampire Diaries," titled "Children of the Damned," after the break...]

Ye Olde Mystic Falls, circa 1864. A horse drawn carriage stops in the road, where a damsel in distress is yelling for help because her husband has been attacked. Unfortunately for the two men inside, the woman is Katherine, and when they get out to assist her she eats one of them! And then she eats the other! She turns to her “dead” husband, who’s revealed to be Damon, still human and learning how to be a vampire. Blood dripping down her lips, Katherine asks Damon for a kiss, but he’s way grossed out and hesitates. You know what they say, practice makes perfect. Even when it comes to getting used to the taste of human blood.

Present Day: Stefan and Elena are spooning! Aww. Romantic, until Damon interrupts to get the investigative ménage a trois started. “We have lots to do, now that we’re all…friends,” he says. Damon assigns Elena to track down Jonathan Gilbert’s notebook, which we learned last week is the key to finding the Grimoire.

WTF is a Grimoire anyway, Elena asks? It’s a witch’s cookbook of spells, the Salvatores explain. Duh. But who was helping Pizza Guy last week, they still wonder. Damon leaves so that Stefan and Elena can resume making out and bed sheet humping.

…which morphs into Damon bed sheet humping with Vampire Katherine in the 19th century. They’re interrupted by witch Emily, who announces that Pearl is here to see her.

Downstairs, Katherine and Pearl speak privately. Katherine’s raising eyebrows by tapping BOTH Salvatore brothers at once, which is something that concerns Pearl, who’s worried that their vampire secret will get out if they attract too much attention. She gives Katherine an elixir made of vervain that the townspeople are starting to circulate. Pearl wants to move on to another town together but Katherine’s not ready. Pearl’s teenage daughter runs over…and it’s Jeremy’s friend-secret vampire Anna! In a bonnet!

Back in the present, Anna calls Jeremy as Ben gets out of the shower, indicating that they’re on intimate terms. He’s a new-ish vampire, so he forgets things like how the sun gets all burny on his skin. Ben wants to kill, already, but Anna’s not ready to unleash him. She says she turned him because he lacked purpose and he was sad; vampirism, nature’s antidepressant!

Back at the Gilbert’s, Elena and Stefan talk Damon. She thinks he’s done all of his dastardly things for love, which IS kind of sweet. But Stefan says that for 145 years, Damon’s screwed him every chance he gets, so he doesn’t trust him. He thinks that if the tomb is opened, tons of people will die. Meanwhile, Elena discovers something in an old family box next to a picture of Jonathan Gilbert. It’s a weird muzzle-like contraption. Jeeremy walks in and tells him he told Alaric all about Jonathan, and everyone’s all, whaaaat?

Back in the olden times, Damon and Stefan’s dad is…James Remar! He’s one of the vampire-hunting townsfolk, and promises his fellow hunters to have both of his boys fighting on the side of good when the vampire killing commences.

At the school, Alaric is being watched by Anna, who ghost-walks by him like monsters do in horror movies. He senses her and runs out to grab a bag from a locker, inside which is… a homemade stake-gun! He returns to the classroom and fires! Only it’s not Anna, it’s Stefan, who easily catches the stake mid-air.

Alaric desperately reloads, but Stefan flies across the room to stop him. He throws Alaric down so they can talk. Stefan is impressed by his air gun, and demands to know what his deal is. They get to talking. Alaric admits that he’s a historian who discovered Mystic Falls lore; his wife was a parapsychologist who came to town to research the supernatural, only a vampire killed her. Stefan asks where the Gilbert journal is, but it’s gone missing.

Anna has it! As she reads through it, a man’s voice-over begins. Jonathan Gilbert writes about Pearl, a beautiful woman he’s spotted around town. Gilbert finds Pearl and Katherine talking in town and asks her on a walk, perchance to court her.

Also walking and talking is Stefan and Damon, who are both adorably long-haired in the 19th century. Their father admonishes Damon for deserting the Confederate Army, but he needs his sons’ help; he wants them to help him hunt the vampires that have come to Mystic Falls.

Back in the present, Alaric tells Stefan that Damon killed his wife, but he doesn’t just want revenge; he wants to know what happened to her, because her body disappeared after Damon’s attack. Stefan advises Alaric to never tell Damon what he knows, else Damon will kill him in a hot second. He offers Alaric his help.

Damon flirts with Elena while he cooks the Gilberts dinner. He asks her straight up if he can trust Stefan, and she lies and tells him he can. Damon still doubts. He trusted Stefan back in the day not to tell their dad that Katherine was a vampire, but apparently that didn’t end well. Elena comes to understand that Damon will accept Stefan’s help to get Katherine back, but will be really pissed if anyone tries to stop him.

Family night continues. Damon plays video games with Jeremy; apparently vampire skills make you really good at games. Jeremy tells him about Anna: a hot, but weird chick who keeps calling him. “Hot trumps weird,” Damon tells him.

Bonnie’s on her date with Ben; they went to karaoke and had a blast! He’s already asking for another date. Ben fishes for info, asking about Elena Gilbert because that’s his job. Unsuspecting Bonnie tells him that she and Elena are close as sisters, and that she’d die for her, which we now suspect might happen sometime in the future.

Stefan arrives and tells Damon and Elena that someone took Jonathan Gilbert’s journal from Alaric. But who else knew about it? Damon interrogates Jeremy, who’s weirded out that everyone’s interested all of a sudden in his ancestor’s diary. He tells them that Anna knew about it, and that she wants to meet up at the Grill later tonight.

While Damon goes off to track Anna, Stefan and Elena pore over a copy of Jonathan Gilbert’s journal that Alaric had. Meanwhile, Jeremy meets Anna at the Grill as Damon watches from a distance; he gets a glimpse of Anna and trips down memory lane…

Back in 1864, Human Damon warns Pearl and Katherine that they should be careful as the human vampire hunters are getting closer to catching them. Damon remembers meeting Pearl’s daughter, Annabelle. Present Damon realizes she and Anna are the same person. Duh-duh-duhnn!

Elena finds a notation from Jonathan Gilbert that mentions Giuseppe Salvatore, Stefan and Damon’s father. Back in the past, Stefan and his dad talk about his secret writings, which he promises to carry to his grave. But Stefan has a problem with his dad’s vampire hunting plan; what if not every vampire is evil? Shouldn’t we be open minded to those who are different from us? Daddy Salvatore answers by telling him that humans who help vampires will be destroyed as well.

In the woods in the middle of the night, Elena and Stefan are digging something up by firelight. In the past, Stefan wonders what Katherine’s wearing around her neck; it’s from Emily, she says. She and Stefan get steamy and in the middle of foreplay she nibbles on his neck. But Stefan’s been fed vervain by suspicious Daddy Salvatore and his blood poisons Katherine, who falls to the floor. Daddy Salvatore busts in and chides Stefan for being weak enough to fall for a vampire’s charms, sending him to fetch the sheriff. A bewildered Stefan runs out the door, leaving Katherine at the mercy of his father.

Damon catches Anna at the Mystic Grill, who’s stronger than she looks. She’s been wondering how long it would take for him to find her, and they retire to her hotel room to talk. She’s been here the whole time, watching Damon futz around town trying to bring Katherine back. Turns out Anna was the one who turned Logan the News Guy, because using other people to do her dirty work is her M.O. She’s tracked the key to opening the tomb down to something hidden by Daddy Salvatore, and asks Damon to help her. But Damon’s a solo kind of guy, and takes Jonathan Gilbert’s journal for himself.

The date’s going so well that Bonnie makes a move on Ben, but she feels something evil when she kisses him and tries to sneak off. He grabs her, and we have a feeling the romance is over.

Stefan and Elena find the buried object they were looking for; it’s ANOTHER old journal. As Stefan begins leafing through the pages, Damon shows up. Stefan is forced to finally tell Damon that he never meant to help him, which just hurts Damon’s feelings more. He’s also hurt by Elena’s betrayal, because he actually trusted her when she lied to him. Poor Damon! He’s so mad, he could hurt someone. Someone named Elena!

Stefan knows Damon won’t kill Elena – but he WILL turn her into a vampire! Damon forces Elena to drink his blood, threatening to kill her and turn her unless Stefan gives him what he wants. It’s a no brainer, of course; Stefan throws down the journal and leaves with Elena under his arm.

Damon flashes back to the fateful night when he lost Katherine. With a mob approaching the Salvatore house, he tried to stop Daddy Salvatore from giving Katherine over to the vampire killers. We see what that contraption was – a vampire muzzle, which Daddy Salvatore placed over Katherine’s mouth.

Stefan finds a frantic Damon following the angry mob, and promises to help him. But Damon’s already pissed; he blames Stefan for revealing Katherine to the townsfolk, and runs off to be angry at him for the next 145 years.

Stefan goes downstairs to get Elena some aspirin, because her head is pounding with all that Damon blood in her. But Jenna and Jeremy reveal that Anna’s been in the house – and still could be.

Back in the past, Pearl tries to save Katherine but runs into Jonathan Gilbert, whose vampire compass goes nuts, indicating that Pearl is also a bloodsucker. Will his schoolboy crush prevent him from turning her in? Nope. He rats Pearl out to the mob and she’s shot and captured while trying to escape. Meanwhile, Stefan sees witchy Emily promise a distraught Annabelle that she’ll protect Katherine and Pearl, and Emily locks eyes with him.

Stefan puts two and two together, realizing who Anna is, and races upstairs to reach Elena before Anna does. But it’s too late; the window’s open, and Elena’s gone. Nooooooo!

Next week: Almost-vampire Elena is held captive, and Damon refuses to help Stefan save her!