Elena, still full of questions, finally put two and two together. Enzo was the Augustine vampire that killed Megan. Apparently Megan's parents helped fund Grayson's project. They didn't know about Augustine, but they knew he had an "unregulated compound that could cure most injuries." But as Megan got older, she grew suspicious and one day found herself a little too close to a very hungry Enzo, and that was lights out for her. Speaking of lights about ready to go out, Elena was ready for the next phase of testing. Hurry up, boys!
Stefan stepped out of the classroom to call and threaten Wes, but he threatened Stefan right back. That Wes guy has some serious balls. Inside the classroom, Enzo really wanted to tell his story. When they interrupted his tale to talk about Elena, he ripped a desk out of the ground and threw it... so they listened. Stefan learned all about his brother's betrayal and yet when Enzo looked for a reaction from him, he stood by his brother: "You didn't die, obviously." Nope, Enzo was saved by a scientist and put right back on the table.
As soon as Enzo left the room, Stefan started asking questions, but Damon cared less about Enzo and more about killing Aaron. And after Damon threatened to gauge Aaron's "sad little eyes" out of his "sad little head,"Aaron used files of his family's history as leverage, which was a very "timely revelation" on his part. Wes clearly didn't care about Aaron, so he was going to save himself. Stefan and Aaron headed out after Enzo, who had returned with booze in hand, requested Damon stay with him.
Back in Mystic Falls, Nadia's big idea to save Katherine was spirit possession. Technically, because Katherine's father was a traveler, it meant she was too. She just needed to learn the spell. Katherine wasn't exactly a fan of traveler magic, as her father had banned it from them when they were young. And once she became a vamp, well, that was that. Nadia informed her that because being a traveler was in her blood, she could live inside someone else's body. "Stefan actually likes this body," Katherine said. Then, Nadia realized that Katherine's previous question about forgiveness was actually about Stefan and not some great mother-daughter moment. For Katherine, knowing Stefan still cared would make dying a little less lonely. Sadly, that didn't help her relationship with Nadia, who told her to go kill herself and "see if anyone misses you." Ouch.
Meanwhile, Enzo and Damon discussed cricket, drawing, and the poison Wes had injected Enzo with. It was stopping his heart, and he would dessicate without the antidote. Damon tried to convince his ex-friend that they could kill Wes together, but Enzo was more interested in whether Damon thought about him after he left. Just as Damon thought he'd convinced Enzo to go back as a team, Enzo informed him that he wanted the antidote, which meant he had to kill Damon. First step: He threw Damon through a window. The fight didn't last long. Damon was stronger, and Enzo dessicated before he could do any real damage.
The good news was that Stefan was having more luck with Aaron. Well, not at first. Aaron tried to shoot him, and not surprisingly failed. Stefan then choked him until Aaron started talking about how Damon killed his family. You could tell Stefan was genuinely disappointed in his brother. After Aaron begged Stefan to kill him so that Damon couldn't have the satisfaction, Stefan said, "You know, not all of us are like my brother." But before he left, Aaron handed over his Augustine files.
In flashback number two, young Elena could hear screaming in her father's basement. Grayson grabbed her before she could reach the door. He told her that "daddy" was going to save a little girl's life. "Pretty cool, huh?" More like creepy. When Elena woke up, Wes was ready to inject her with the thing that would make her salivate at the smell of vamp blood. Just as he stabbed her, Stefan showed up. Elena head-butted Wes, and Stefan helped her out of there, but not before she grabbed her father's journal on the way. Two things: First, that was a great moment between them. I love hero Stefan. Two, why didn't they destroy the rest of that serum? Guys, it was in a glass jar. It was practically asking for it.
NEXT: The veins in Damon's neck mean business!