In this book, Elena and Stefan have lived for years since destroying Klaus. Elena has been attacked over and over by the powerful and vengeful Old Ones. So far, as Stefan and Meredith have been hunting the Old Ones that want revenge for Elena killing Klaus. Stefan, Meredith and Elena attack an Old One named Celine who claims that she knows her secret of having powers that protect her from any supernatural harm and uses the cave to fall on Elena. Elena luckily survives and Meredith and Stefan kill Celine with her Principle Guardian Blood. Meanwhile, Damon and Katherine have been traveling Europe with Katherine turning any handsome young man she finds and dumping them when she gets bored with them. Damon is successful in charming young girls without the use of his Powers and finds willing blood-downers to drink from. Damon and Katherine and Katherine's vampire boy-toy are attacked suddenly by a group of powerful and seemingly unkillable vampires. Katherine's boyfriend gets killed, but she and Damon escape successfully.
Back in Dalcrest, Elena is driving her car when it suddenly speeds up exceedingly and and she crashes.
Elena is saved by another Vampire Hunter named Jack. Elena and her friends establish that the Old Ones know of the weakness to her protection against supernatural powers, had Jack not saved her, the car would've exploded leading to an un-supernatural death. The Old Ones want Elena dead. Bonnie McCullough and her boyfriend Zander go to Mrs. Flowers' and find that she has a guest that tells Bonnie that she is also a witch and has the powers of illusion. Mrs. Flowers asks Bonnie to go to an organisation that will teach her more about her own aura and Powers. Bonnie is reluctant, but Zander encourages her to go and increase her knowledge of her powers and her strength and heritage and Bonnie agrees. Bonnie leaves the next morning.
Jack tells Elena and her friends that the Old One that they're up against is named Solomon, a very ancient and very powerful vampire with much more power than Klaus or any other Old One they've fought.
Elena and Stefan come home one night to find that Elena's cat has been killed with a warning from Solomon who has also stolen their best weapons.
Elena and her friends are later attacked by compelled humans who claim to be sent by Solomon.
They go to a location where the humans claim that Solomon told them to go, and Elena and her friends go instead only to find a trap waiting for them and almost burn to death. Damon calls Stefan and indirectly asks for help (doesn't tell him about Katherine's death) only to be let down by his younger brother. Elsewhere, Bonnie gets settled with her group of witches and psychics and feels like she is understood by people who are like her. Damon and Katherine have still been attacked by powerful vampires who refuse to die. Katherine (whom Damon had been falling in love with) sadly gets killed by one of the Immortal Vampires and drops in Damon's arms before he temporarily kills that vampire. Stefan, Meredith, Matt, Jack, the Original Pack and other vampire hunters and the protagonists attack and find (with the help of Elena's and Andres's Guardian Powers) the place where they believe Solomon to be. They succeed in killing all his minions. When they think they have won, Solomon reveals himself, being very handsome and powerful he holds them all in place and causes one of the vampire hunters, Trinity to get a nosebleed. He walks around the room examining them with eyes glowing gold. Andres summons deep Nature Magic and breaks Solomon's Power Hold over them and Stefan slices Solomon in half with Elena's blood.
Later, they discover that Solomon isn't dead and that he had possessed a man named Gabriel and now has possessed Trinity, as her eyes are now gold and not the original color they used to be - Solomon has possessed Trinity. The other hunters and Elena struggle with killing a fomer member for reasons of not being sure whether or not Trinity's consciousness is still in there. Stefan on the other hand, has already decided to kill Trinity along with Meredith and Jack much to Elena's distaste. Stefan feels Katherine's spirit say goodbye to him and instantly knows that Katherine is dead. Bonnie, elsewhere, has been growing stronger with her witchcraft and psychic energy. She learns to channel her power into a stone on a necklace Damon had given her for her birthday and channels her new friends's energy to practise growing her own. Damon finds a lab in his whereabouts where he believes the vampires are experimenting and creating a new incredible unkillable species. Elena and Matt soon learn that Solomon isn't to be messed with, but are saved by Elena's Guardian Powers. Meredith goes for a jog and sees a couple making out, then she realizes that they aren't a couple and that it is Trinity who is now somehow a vampire. But Trinity now has golden glowing eyes meaning that Solomon truly resides in so Meredith tries to attack only to be neutrelized by Trinity/Solomon who lets her go. Meredith runs home and tells them all what happened.
Elena, Matt and a few other hunters still believe Trinity's still in there with further conflicts between the group. Andres is butchered by Solomon, breaking Elena's heart and fueling much more anger towards the Old One. Elena gets a phonecall from Damon who tells her about Katherine and about his fight and that he asked Stefan for help, but he refused, much to Elena's annoyance. She says she is sorry for Katherine's death and she knows how Damon felt about her hinting that Damon had been falling in love with Elena's half-sister. Elena asks Stefan if he had refused to help Damon which Stefan does not deny and says that he needed to stay and protect her. Elena says that she is not the only girl in the world, but Stefan answers that to him, she is and frustrating Elena. Bonnie returns after an epic magical performance with her Psychic Witch friends. She has a party waiting for her and she notices the tention everyone carries. But her best friends tell her that she shouldn't worry and they would tell her about it the next morning. The werewolves beg Bonnie to do a magic trick playfully, which Bonnie accepts to and uses her new and enhanced Psychic and Witch powers to channel the life and energy and love and warmth of her friend's auras. She levitates on of the werewolves to the roof harder than she had expected to, but he laughs and all her friends join him.
The next day, Bonnie demands details of everything that's going on and Meredith and Elena tell her. Bonnie thinks that they have it wrong and that Solomon isn't an entity that possesses them, but an entity that is working from a faraway place by using a kind of psychic link to control the poeple the gang that were possessed. Being an Old One, Bonnie believes that while doing this, some of his lifeforce and much of his Power is used up and thus the vessel also gains vampirism, but Solomon's true body is somewhere close by and if they kill him there, the possession will break and they would have won once and for all. Elena is relieved by the fact that Trinity lives somewhere in there and Bonnie and her decide to use their powers to try to find him. Damon finds out that the doctor who's been creating these Immortal unkillable vampires plans to kill all other vampires that can be killed including the Old Ones. Damon finds a whole list of them:
- Klaus (crossed out)
- Celine (crossed out)
- Davos (crossed out)
- Katherine von Swartzschild (crossed out)
Most of the other names are crossed out, leaving the Salvatores and Solomon uncrossed. Meanwhile, Elena and the protagonists follow Elena and Bonnie into the layer of Solomon. Elena uses her Guardian Powers to find his aura followed by the Pack, Meredith, Alaric, Stefan, the Hunters and Bonnie. Solomon shows his true self to them and the protagonist thinks that he does not look so impressive, as when he was in Gabriel's body, he was very handsome and in Trinity he was beautiful. Now he is small and not so youthful and not handsome at all. Solomon has them held with a telekinetic hold over all the protagonists and they can't move. Bonnie's Druid Powers have grown stronger since the last time and she is able to counter and disrupt the telekinetic hold with a little held from Elena's pure aura. Stefan quickly kills Solomon and they win unharmed and Solomon is truly dead. They have a party at Stefan and Elena's apartment. Stefan and Elena try to walk out, but are blocked by Jack and he stabs Stefan right after she sees his aura is demonic and dark and vampiric and Jack escapes. Elena is extremely devastated and heartbroken when she sees that Stefan is dying and tries to save him with her Principle Guardian Powers without much luck. Stefan tells her to be strong and that he loves her with a heartwarming goodbye and he dies. They have a funeral and Elena refuses to accept his death and doesn't do a speech for Stefan's funeral. Damon has returned and too refuses to accept it. The book ends with Elena and Damon declaring VENGEANCE with Elena's anger fueling her powers to the point where it burned inside her.