Last week on the Vampire Diaries, viewers were shocked to discover that Alaric (Matthew Davis) was the Mystic Falls serial killer. This week, the series dives deeper into discovering why his life-saving magic ring is causing the drastic and deadly mood swing.

Dr. Meredith Fell (Torrey Devitto) has been trying to protect Alaric, and runs tests on him to see if he can be treated medically. During one of these tests, the audience sees a change go across Alaric's face. It's at that point that Vampire Diaries fans realize that Alaric truly has another person taking over his body. With a medical cure looking slim, Elena (Nina Dobrev) decides to ask Bonnie (Kat Graham) for help, seeing that a witch in her family made the magic ring that is changing Alaric.

Unfortunately for Elena, Bonnie is still upset with her after Damon (Ian Somerhalder) turned Bonnie's mother, Abby (Persia White), into a vampire a couple weeks ago. As Abby completes her transition into becoming a vampire, she is struggling how to control and lead her new life with Bonnie, and Jamie (Robert Ri'chard), her step son.

Meanwhile, the town of Mystic Falls is as busy as ever, with the old Wickery Bridge (which just so happens to be where Elena's parents died) being rebuilt. It's at a party celebrating the renewal of the bridge, that Damon spots an old friend - Sage (Cassidy Freeman). Last week, Sage showed up in flashbacks, and this week, actually makes an appearance in Mystic Falls as she searches for her one true love, original vampire Finn. An old rivalry reignites when Finn's sister Rebekah spots Sage, who quickly informs her that Finn is long gone.

In the world of former lovers Elena and Stephen (Paul Wesley), the usual tension is mounting with Stephen's stress eating. As Elena continues searching for answers to help Alaric, Stephen informs her about what happened to Samantha Gilbert, Elena's ancestor who wore the ring before Alaric did. After Samantha Gilbert admitted to going on the murder spree in 1912, she was admitted into an insane asylum, where she attempted to give herself a lobotomy with a sewing needle and ended up bleeding to death in her cell.

The tip of the Elena love triangle, Damon, has set up a plan with Sage to get inside Rebekah's head to see what exactly she has been plotting the last couple of weeks.  So what's the plan? To get Rebekah jealous of Sage and Damon's relationship.

Bonnie, on the other hand, is trying to get into her mother's head. After Abby accidentally bites an already frightened Jamie, she doubts whether she did the right thing by transforming into a vampire instead of just letting herself die. Bonnie's shifts her focus though when she finds out about Alaric's situation, and how grim he is about surviving his craziness. Bonnie believes she can reverse the effects of the ring induced craziness with magic, but she needs a personal object of Alaric's that he wore before he began wearing the ring. Elena leaves Alaric alone with Dr. Fell to get a personal object from his house.

At Damon and Stephen's residence, Damon and Sage's plan seems to be working. After successfully seducing Rebekah, Sage comes in to read what's on her mind. Damon finally figures out that Rebekah is after the white oak tree, the only thing that can kill her and her family of original vampires. In a great twist, Damon discovers that the white oak tree in question had been chopped down years ago, and was used to build the towns Wickery Bridge, the same bridge that just so happens to be being torn down and rebuilt. The only problem now is Sage, who realizes that the white oak wood could kill her beloved Finn. Damon promises her that he won't try to kill Finn, only Rebekah, but unfortunately for him, Sage realizes he is lying.

Stephen meets up with Elena at Alaric's house, and tells her that even though he has stopped wearing the ring, his crazy violent acts can still occur. Their urgency to get back to Alaric and Dr. Fell gets put on the back burner when they discover a draw filled with gruesome images of all the murders he committed, along with a hit list and a creepy note to Jeremy, Elena's brother, who also has a life-saving ring similar to Alaric's.

As Elena and Stephen look at the shocking pictures of Alaric's crimes, the crazy side of Alaric decides to take over while he is left alone with Dr. Fell. Emptying out syringes that Dr. Fell was going to use to sedate him in an emergency, Alaric attacks her with a knife.

So why is this crazy side of Alaric murdering founding family council members of Mystic Falls. Council members have been ignoring their responsibility to protect the town by looking the other way from vampires, Alaric tells Dr. Fell before she is able to escape into a bathroom.

When Elena and Stephen finally return, they discover blood on the floor and a shifty-looking Alaric. As he tries to attack her, Stephen steps in, knocking him unconscious. It's then that Stephen smells blood, and him and Elena run upstairs to help Dr. Fell who lost a lot of blood from her knife encounter with Alaric. With Dr. Fell healed, Bonnie comes to help Alaric with magic, and is able to help stop the mad man inside him with herbs that he has to take twice a day.

As Elena and Bonnie make up their relationship after she restores Alaric back to normal, Bonnie is about to lose a relationship. While she was off helping Alaric, Abby decides that she can't be around Bonnie and Jamie and runs off.

Damon has also had someone turn their back on him. Once Sage realized that the original vampires are linked together, with one death killing them all, Sage tells Rebekah, who sets the wood from the bridge on fire.

Damon threatens Sage that when he does figure out how to kill the originals, he is going to start with Finn.  While Sage doesn't think that that day will be for a while with the white oak wood burning before them, Damon as usual has a trick up his sleeve. Returning home to Stephen, he is carrying a wrapped up package. Inside is the old Wickery Bridge sign, something that Sage and Rebekah overlooked in their burning spree. Let's kill some originals, Damon tells Stephen.

An intense episode, viewers finally get a peek at Jeremy, who has been missing in the show in recent weeks after Elena sent him out of town for his safety. Elena calls to check up on him, where he seems to be living a stress-free life compared to what Elena has going on in Mystic Falls.

Elena's stress is only going to expand in next week's episode when the battle begins.