Alone with Everybody

Rumors begin to spread about the remaining white oak bullet that can kill an Original vampire, leading villains of the past to try to take down Klaus once and for all. Elijah urges his siblings to lie low at the compound while Marcel, Vincent and Josh chase down a lead involving a mysterious vampire named Sofya, who has the bullet and is working for a powerful mystery man who wants the Originals dead. Tensions inside the compound build as Kol wants revenge on Finn. Finn wants to go back to a witch body, still hating vampires. Davina bounds Finn to his vampire body for his whole life. Klaus and Hayley seek shelter with her former pack and learn that someone is hunting werewolves for an unknown reason. The White Oak Bullet is found and instead of burning it, Elijah entrusts it to Freya. Vincent, forced by the Ancestors, knocks out Freya, who wakes up in the lair of the mystery man, Lucien.

Plot summary from Wikipedia (CC BY-SA 4.0). Source