Elena, Clay, Jeremy, Nick, Paige and Cain arrive in Boston, with some doing better than others. Jeremy breaks the news about poor Logan as Nick struggles to control his transformation.
Elena is worried, as the "Dead by Dawn" vision is back. It's gonna be a rough night.
Nick confesses to Jeremy that he met his mother, Lily. He wants love in his life more than anything else -- he vows not to change into a wolf, for fear he may stay that way forever come dawn if The Undoing completes its course.
Aleister put a blocking spell on the building's doors, but Clay takes care of it the old-fashioned way. An attack by security guards under Aleister's control causes the team to split up: Clay & Cain, Paige & Elena and Jeremy & Nick.
En route to the Ritual Room, Aleister casts a particularly nasty spell on Paige to keep her from pursuing him.
Paige suddenly attacks Elena. Elena tells her to rally and resist Aleister's dark filthy magic.
Paige rejects the spell and vomits black goo. Whew, that was a close one.
As the door to the Ritual Room can only be opened by a coven witch, Aleister forces Savannah to do her thing.
In the Ritual Room, Ruth attempts to cut Aleister and use his blood in a spell that will destroy him utterly, though in doing so she breaks the safety of her circle. Aleister prepares to make her suffer but discovers he has no powers in this room.
Aleister takes Ruth's green ring and his wounds heal. Uh-oh.
As she opens the door to the Ritual Room, Paige tells Elena that if she can't kill Aleister, then Savannah is the conduit -- do whatcha gotta do, lady.
In another part of the building, Clay and Cain are pinned down by a trigger-happy security guard under Aleister's control.
As he doesn't want Clay to end up like him and live his life without his lady, Cain sacrifices himself as he rushes the security guard, taking several bullets. As Cain dies, he gives the guard's key card to Clay. Huzzah Cain!
Elena enters the Ritual Room and picks a fight with Aleister, though Aleister ends up stabbing her in the stomach. No!!
Elena pulls the blade from her stomach and uses it to cut Savannah's arm, removing Stuffy the Critter and releasing her from Aleister's control.
Clara grabs Savannah and makes a run for it with Aleister as Elena dies in Clay's arms. ELENA!!!
Nick holds some security guards at bay whilst Paige enters the Ritual Room.
One last spell for the road. Ruth prepares to resurrect Elena ... at the cost of her own life. Whoa!
An enraged Savannah tells Aleister that she'll make him suffer for what she did to Elena. Clara tells Savannah that she'll soon be possessing her body, though Savannah tells her she won't let her in. Go littlest witch!
Ruth's final bit of magic worked. Elena rushes out to find Aleister as Paige cradles her dead mother.
Clay, not knowing that Elena is alive, transforms into a wolf (why live as a human without his lady?) and attacks Aleister.
However, because the coven leader, Ruth, is now dead, Aleister regains his powers. He sends Clay-wolf flying across the room.
Savannah takes advantage of the distraction to work a bit of dark magic that Aleister himself taught her. Clara chokes n' convulses until she's dead, dead, dead. Yes, Savannah!
Savannah then faces off against Aleister. Who is now the stronger: the master or the student?
As Elena enters looking for another fight, Aleister turns his magic toward her, though a quick counter-spell from Savannah leaves him helpless and allows Elena to drown him like the damn witch he is. The rising sun provides dramatic back-lighting.
As the sun rises, Aleister is dead, the witches are still alive and the werewolves are still werewolves. The Undoing has been foiled. Whew!
Jeremy promises Paige and Savannah that he'll never turn them away should they ever come to him in need of help.
Paige, who's now the coven leader, says goodbye to Nick. They love each other deeply, but a witch and a werewolf ... that's just asking for trouble.
Elena and Clay are reunited. Love protects them. That's right, darlin'.
Looking over the pile of dead bodies, Savannah can't help but think this is all her fault. Elena assures her it's not.
As Elena takes Savannah's hand, she has a new vision: herself, covered in blood, calmly sitting at Jeremy's desk as Stonehaven burns around her.