Maybe Elena's hometown should be renamed Flashback Falls—cause here we go again! To 2009, though, not 1864, where we find out how Mason activated the curse, i.e. killed someone. A drunk friend picked a fight with Mason at a bar over some alleged philandering, and in the process of fighting, Mason accidentally killed him. Tough break! Mason tells Tyler this as a warning: "All it takes is an accident." Foreshadowing much!?! In return, Tyler promised to hand over the moonstone. Only, since Mason won't reveal why he wants it, Tyler pretends that he doesn't have it.
Stefan and Elena are still maintaining their fighting façade. To ensure that through the fake arguing they'll know what's real and what's not, they devise a code. Stefan saying, "I can’t do this anymore" means "I love you," and Elena saying "Fine Stefan, whatever" means "I love you, too." Aww!
Since this wouldn't be Mystic Falls without yet another cheesy town event, say hello to the Historical Society Volunteer Day. Everyone's there, creating a prime setting for drama. Stefan tries to make peace with Mason, and although they shake hands, it's evident that Mason's still out for Damon's blood. Mason tries to get in with Caroline's mom, Liz, but she denies knowing anything about a "secret council." So he plays the only hand he has, informing her that there are two vampires in town. Now remember, Damon and Liz are buddies, so she’s pretty skeptical that he and Stefan are vamps, so Mason offers to prove it.
Caroline gobbles up Stefan and Elena's fighting charade, but Damon tells Stefan that he sees right through it. Damon takes a swig of lemonade and immediately falls over. Mason spiked it with vervain! Unluckily for him, Liz sees the whole thing and calls for backup to take out the Salvatores. As she's leaving, Caroline corners her and officially makes her feel like Worst Mom of the Year for leaving. Her mom's distress piques her interest, though, so Caroline starts eavesdropping on her surroundings.
Stefan and Damon corner Mason in the woods, but just as they’re about to kill him, wooden bullets come flying from all directions. Liz and a few fellow officers inject the boys with vervain and carry them into a cave. Of course, Caroline hears it all and leads Elena to the cave—after fighting Mason and totally taking him down. That girl kicks butt! Just as the Salvatores are about to be staked, Elena storms in, followed by Caroline, who kills the cops and sucks their blood. Yeesh!
Once the guys come to, Damon feeds on one of the dead cops, but Stefan refuses. Caroline asks her mom to keep the secret, but Liz looks completely horrified, mortified and petrified. Can you blame her? Her daughter has become what she despises the most. Oh, the irony! When Liz finally speaks, she says that she’d rather be dead than have a vampire daughter. Damon comes thisclose to fulfilling her wish and killing her. Instead, he decides to keep her in the basement until the vervain leaves her system and compel her to forget everything. In a truly painful moment, Liz says that Caroline isn’t her daughter anymore, which, of course, Caroline overhears. Can something good PLEASE happen to Caroline for once?
Stefan contemplates drinking donor blood so that he can be stronger and properly protect Elena. His theory is that if he drinks a little daily, like Katherine did with the vervain, he can become immune to its negative effects but still reap its benefits. Sounds a little far-fetched if you ask me. They fight about it, and Elena goes to comfort Caroline, who finally tells Elena about Katherine’s meddling (which of course, Elena already knows about).
Once Caroline's asleep, Elena thanks Damon for showing Liz mercy. "That’s the Damon who was my friend," she says. Damon reveals that Stefan didn't drink the blood. Understanding the situation, Elena goes to Stefan, cuts her hand and offers it to him. In a very Sookie-Bill "True Blood"-esque moment, Stefan hungrily sucks her blood, then they passionately kiss. Hotness!
Okay, so while all this was going down, Jeremy and Tyler were entertaining lady-friends at the Lockwood's. One of the chicks asks to see Jeremy’s sketches, which all depict wolves. Tyler corners Jeremy away from the ladies, and Jeremy admits that he knows about the Lockwood "secret." Tyler tells Jeremy everything: Mason, the curse, the moonstone. Then, one of the girls comes in and drunkenly snatches the stone away in what she intends as a flirty gesture. Pissed off, Tyler corners her and accidentally pushes her down the stairs as he wrestles the stone back. Thankfully, the girl survives, but Tyler’s seriously shaken by his near-brush with activating the curse. Later that evening, he tells Mason what happened and finally hands over the moonstone.
And this is where it gets real shocking. Stone in hand, Mason gets into the passenger seat of a waiting car. Who's driving? KATHERINE! Apparently, Katherine set off the chain of events last year that caused Mason to kill his friend. Once he hands her the moonstone, they kiss hardcore. WTF? Mason must believe that Katherine loves him—he doesn’t know anything about her history with the Salvatores!
On a side note, Nina Dobrev's hot costar makeout tally is up to, what, like three or four guys now? Lucky girl.
Will drinking human blood cause Stefan to be a jerk all over again? Will Mason find out about Katherine and the Salvatores? What's going to happen to Caroline and her mom?