The episode begins in the woods, and one of the five hunters has Damon tied to a tree. He knows all about the crew from Mystic Falls and what they're up to. His mark completed two days ago for no apparent reason, when they killed Kol. He doesn't appreciate Damon's glib approach, so he sticks a metal rod in Damon's neck. His name is Galen. Elena in the meantime calls Caroline to update her on Shane's shenanigans and Damon's disappearance. Elena wants help translating Jeremy's tattoos and wants her to get the sword from Klaus. Caroline goes to look for it. Shane takes Jeremy, Bonnie and Massak the witch to the cave where Silas is.
Massak bails, demanding his payment from Shane. He wants the tombstone, which is valuable in witch circles. Caroline and Tyler come back to the Gilbert's house to show Klaus they've found his sword. They're working on decoding the cryptex in the handle. Klaus says it's in Aramaic, which could take days or weeks to translate. Turns out, he speaks Aramaic. Back on the island, Elena is surprised that Stefan didn't tell her he wanted to take the cure. Galen leads Damon through the woods, bound by Vervane-soaked ropes to hold him. Galen's planning to use Damon as leverage to make Bonnie open the crypt so he can get to Silas and kill him. Damon tries to explain Bonnie's going to open it anyway to get the cure.
Caroline and Tyler use the internet to try to translate Jeremy's tattoo, but get nowhere. Klaus helps, saying they need a witch and a "hunter in full bloom." He translates the cryptex: "Silas rests on the far side, the means of his destruction at hand". Klaus sees something in the cryptex and tells Caroline how to open a secret compartment. Galen in the meantime explains to Damon that he needs to use the cure to kill Silas. Klaus and Galen explain: There is only one dose. Back in the cave, Bonnie slowly lowers down to join Jeremy. She falls and cuts her hand, bleeding on the stone floor. With Shane out of earshot, Bonnie promises Jeremy she won't let Shane raise Silas, even if it means killing Shane herself.
Her blood seeps down to the crypt. Caroline on the other hand sends Rebekah their translation. Rebekah can't believe Klaus helped. He tells her he hopes she gets her wish to be human then, before Caroline can hang up, he tells her there's only one dose. Damon asks Galen why he saved Jeremy, but Galen denies throwing the mystery hatchet. They come upon a dead body in the woods. Down at the bottom of the cave, Shane leads Bonnie to the door she needs to open, after reminding her that if anything happens to him, something worse will happen to her. Rebekah doesn't tell Elena and Stefan about the one dose. They come to a cliff above a pond, hundreds of feet up.
Elena jumps first, and then when she's alone with Stefan, Rebekah tells Stefan about the one dose. Shane supervises as Bonnie draws the power of Jeremy's mark, removing it from his skin. In the woods, Galen sees his tattoo disappear as well. The walls start to crumble at the bottom of the well. Rebekah guesses that Stefan would give the cure to Elena. "I'm sorry it couldn't work out the way we all wanted it to" she says. Then she breaks his neck. Elena is hundreds of feed below and helpless. In the cave, Bonnie has opened the way to Silas' crypt. She and Jeremy are unhurt by the falling rocks, but Shane's leg is broken. Bonnie leaves him. In another part of the cave, Galen realizes that if Bonnie already performed the spell to open the way to crypt, he has no need for Damon. He frees him to kill him, but Rebekah finds them.
Elena rejoins Stefan, alive again, at the top of the cliff. She doesn't feel like she can take the cure for herself. "Even if I could be human again, I wouldn't be the person that I was" she says. They'll just have to figure out a way to break her sire bond to Damon when they get home. Elena realizes what's waiting for them at home: a trapped Klaus who isn't going to stay trapped much longer. They have to get the cure to him so they can kill him before he kills them all. Back in Mystic Falls, Tyler freaks out over the idea that Klaus will try to kill him with the first chance he gets. Caroline tries to calm him down and assures him she'll handle it. Back with Galen, Rebekah tries to take him on, but first he shoots her with wooden bullets, then he sticks her with a wooden spike grenade that blasts through her. Damon attacks him, but Galen shoots something that wraps him to a post. Stefan and Elena arrive and Galen jumps down a hole.
Stefan tells Elena to go ahead while he tries to free Damon. Down in the tunnel, Bonnie sees her Grams who tells her Silas can bring her back to life. "All you have to do is reach him and feed him" Grams says. Bonnie starts to walk blindly through the cave, but Jeremy stops her. He points out that if her Grams was really there as a ghost, he'd be able to see her, too. It's a hallucination planted by Silas. They realize that's how Shane was tricked, too. Jeremy tells her to block Silas out and just focus on him. Back in Mystic Falls, Caroline makes the case to Klaus to spare Tyler. Klaus guesses correctly that Caroline doesn't want the cure, she prefers being a vampire. He thinks they're the same, so she suggests he prove it by showing compassion and mercy in sparing Tyler.
He agrees to let Tyler leave town, but then says it's only a head start before he kills him. Back in the cave, Stefan unbinds Damon, who is weak. He tells Stefan to go ahead and help Elena get the cure for herself because it's what she wants. Stefan leaves him. Alone in the cave, Elena hears noises and comes face to face with someone she's not happy to see. In Mystic Falls, Caroline gets choked up saying good-bye again to Tyler. He assures her he'll see her again, but she tells him to try to live a happy life without her. They kiss good-bye. Stefan finds Shane and his broken leg. Shane didn't know about, there only being one dose. Stefan leaves him. Shane sees his dead wife Caitlin again. She assures him everything will be fine.
Bonnie and Jeremy reach Silas's tomb. Jeremy sees a small box in Silas's mummified hands and realizes it couldn't possibly cure every vampire. Silas's arms are fossilized around the box. Bonnie realizes that to get it out, they have to feed him their blood and wake him up. Back in the upper part of the cave, Damon pulls the wooden spikes out of Rebekah to revive her. He says he made peace with the idea he can't control everything and let Elena go for the cure. "You did something selfless, Damon. If I didn't know better, I'd say you were becoming a halfway decent person" she says. Back with Silas, Bonnie is telling Jeremy they'll find a way to the cure without raising Silas, when suddenly she's stabbed from behind by Galen.
He tells Jeremy they have to raise Silas. Galen slices his hand and starts to bleed on Silas. Jeremy attacks him. They fight over what to do with the cure until Galen gets the upper hand. Galen is about to off Jeremy when Elena runs out and grabs Galen. She's ready to end him, but Jeremy reminds her about the hunter's curse, so she knocks him out instead. Back in Mystic Falls, Klaus walks out of the Gilbert's house. He assumes something happened to Bonnie. He tells Caroline he showed kindness, forgiveness and pity because of her. She's unmoved. He leaves. Stefan sees a trail of blood down in the cave and finds Elena, bleeding. "She's here" Elena says.
Back with Silas, Katherine stalls when Jeremy asks her to feed Bonnie to save her. Instead, she gets fed up, cuts him and feeds his wrist to Silas. But Silas wants more, and chomps down on his neck. Katherine takes the cure and runs as Silas drains Jeremy and tosses him aside. The episode ends at this point.