It’s game on for Katherine on “The Vampire Diaries.” After completely taking over Elena’s body in episode 12, the evil doppelganger is ready to live her new life in episode 13, “Total Eclipse of the Heart.” Deleting photos of Damon from her phone and making a shot of Elena and Stefan as her wallpaper, Katherine has gone full blown crazy – and is not stopping until she gets the man-pire that she wants.

Episode 13 kicks off with Katherine continuing to impersonate Elena … and doing a pretty good job with it thanks to a compelled Matt. Putting on a chipper attitude, Katherine begins to attend classes with Bonnie and Caroline (where Bonnie comes across a practicing witch) and even agrees to go to Whitmore College’s Bitter Ball. But impersonating Elena doesn’t mean Katherine is putting Stefan on the backburner (although that’s exactly what she’s doing with Nadia). Instead she invites him to the Bitter Ball dance.

Back in Mystic Falls, Damon is struggling with his break up with Elena. Teaming up with his ex-BFF Enzo, the pair go on a killing spree – murdering Aaron and on the hunt for Dr. Wes. The frightening duo even goes as far as to kidnap Diane, the head of Whitmore security. But when Diane fails to produce answers, Damon and Enzo decide to up their body count.

So, where in the world is Dr. Wes? He’s in an old hospital continuing his vampire experiments on a former janitor named Joey. Dr. Wes has plans on conditioning him to feed on vampires, but the twist is that all his old research is gone. Fortunately he has had an Augustine groupie following his work – a woman named Sloan. The mysterious Sloan offers new funding for his research and protecting if he analyzes some blood she has. But Dr. Wes has no plans of biting … until Sloan reveals that Aaron is dead and his killers are coming for him.

As if that wasn’t enough trouble for Mystic Falls, Tyler catches onto the fact that Nadia is compelling Matt. Managing to convince his friend to drink some verbena, Tyler gets caught by Nadia and ends up with his neck snapped.

The party moves to Whitmore College when Stefan shows up at the Bitter Ball dance and Katherine immediately pulls him out on the dance floor. While Stefan doesn’t think anything of it, Caroline’s watching from the sidelines and does not like what she sees.

Katherine and Stefan talk about Damon, and Katherine (as Elena) tells Stefan that Damon changed her and she doesn’t like who she becomes. She asks Stefan if he likes who she became, but before he can answer Caroline pulls her away. Caroline tries to express that she’s worried that Elena might be leading Stefan on, but doesn’t come right out and say it. And since she won’t say it, Katherine goes back to her flirting.

Meanwhile, Enzo and Damon show up at the dance and end up kidnapping Jeremy in order to force Bonnie to do a locator spell to find Dr. Wes. The only problem? Bonnie’s no longer a witch … so they force her to find one.

As Katherine learns that Jeremy has been kidnapped (and is annoyed that she has to play the poor Elena game), Bonnie turns to her classmate Liv for help. Turns out that Liv has had a bad history with magic and doesn’t know what she’s doing. Scared to hurt someone, Liv stops doing magic – which leads Damon to call Enzo as a form of “encouragement.” Enzo’s form of encouragement is taking plastic wrap and suffocating Jeremy with it. And while Jeremy might seem dead, Elena and Stefan manage to find the two in the old Whitmore house.

Katherine performs CPR on Jeremy (and is disgusted the whole time) and manages to revive him. Stefan fight Enzo, but things are put on hold when Damon enters and tells them that Liv’s spell revealed Dr. Wes’ location – Richmond.

Damon and Enzo prepare to head off without a care in the world, but Stefan warns Damon not to bother coming back. T

“I wasn’t planning on it,” Damon responds.

The terrible twosome arrive at the abandoned Richmond hospital that Dr. Wes has been holed up in and are surprised to find a large group of Traveler’s there (thanks to Sloan). With the Traveler’s using magic to inflict pain on the two vampires, Dr. Wes comes up behind Damon and stabs him with a needle – the same needle that will force Damon to feed on vampires, not humans.

Episode 13 concluded with Matt figuring out that Katherine jumped inside Elena’s body, and Nadia holding his life in her hands. Meanwhile, Stefan remains in the dark about the Elena/ Katherine switch, and Katherine promises to help Stefan not lose Damon.