The remaining vampire covens are on the verge of annihilation by the Lycans. Both species are searching for Selene: the vampires seek justice for the death of Viktor, while the Lycans, led by Marius, intend to use her to locate Eve, whose blood holds the key to building an army of vampire-werewolf hybrids.
Semira, a council member of the Eastern Coven, asks Thomas to plead Selene's case before the council. The plea is successful and the council reluctantly agrees to a pardon in exchange for Selene's help. Selene arrives with David and starts training the coven's neophyte Death Dealers for the upcoming war. Semira and Varga, her ally and lover, later poison Selene, slaughter the trainees and frame her for the atrocity. With Selene in her custody, Semira begins draining her blood, intending to drink it to steal her power. Thomas and David attempt a rescue and manage to save Selene. Unfortunately, Thomas dies in the process.
David and Selene take refuge at the Nordic Coven, pursued by Alexia, an Eastern Coven vampire dispatched by Semira. At Var Dohr, the Nordic Coven stronghold, Elder Vidar reveals that David is the son of Grand Elder Amelia. She and Thomas were in love but were forced to hide their relationship and David's true origins due to Victor's extreme jealousy and possessiveness over Amelia. This makes David the legitimate heir to the Eastern Coven.
Meanwhile, Alexia tells Marius, her secret lover, that Selene is going to the Nordic Coven. Marius and his Lycans attack Var Dohr to get her. Selene and David fight alongside the Nordic vampires, who are led by Vidar's daughter Lena. During the fight, Alexia stabs Selene. Marius demands to know Eve's location, but finds out Selene does not know, so he sounds the retreat. Selene deliberately drowns under the broken ice of the lake, telling herself that 'my time is done'.
At the Eastern Coven, Semira drinks the blood taken from Selene. Alexia returns and informs her of the attack at the Nordic Coven. Semira kills Alexia, telling her that she knew of her secret alliance with Marius. David returns to the Eastern Coven, presents himself as its rightful heir and denounces Semira. Even Varga deserts her, saying his loyalty is to the rightful leader. She is led off to be imprisoned in her room.
The coven comes under attack by Marius and his forces. The Lycans blow holes in the castle's walls, letting in sunlight and killing some vampires. David continues fighting, even using himself to shield several young fighters, to the shock and admiration of Varga. He however finds himself face to face with Marius. Selene suddenly reappears, now Nordic in appearance and wearing a coat over her Death Dealer uniform. It turns out that she was resurrected by the Nordic Coven and now has new powers, including enhanced speed. She swiftly dispatches the Lycans, as the Nordic Coven joins the fight.
As Selene makes her way through the castle, Semira escapes from her room and kills the guards. Selene and David find Marius, but David is waylaid by Semira. During the fight, a drop of Marius' blood lands on Selene's lips and she is suddenly flooded by his memories. She sees Marius capturing Michael Corvin and slitting his throat to collect his blood and consume it. To counter her despair over Michael's death, she bites her own wrist, accessing her own blood memories of time spent with him. Selene then rips out Marius' spine, killing him instantly. Meanwhile, David manages to kill Semira. He shows Marius' severed head to the Lycans and calls on them to collect their wounded and retreat.
In the aftermath, Selene, David, and Lena are chosen as new Elders. It is revealed that after her resurrection at the Nordic Coven, Selene was reunited with Eve, who had been following her mother through their telepathic link, as she had anticipated.
