He was last seen in Where Nothing Stays Buried. The hybrid massacre is indirectly mentioned when Hayley talks about doing horrible things trying to find her parents.Hayley's father and mother are mentioned.They were last seen in Keepers of the House. The cult and Will are mentioned by Mary.She was last seen in Keepers of the House. He was last seen in Keepers of the House. Kol was last seen in No Quarter, Finn was last seen in Behind the Black Horizon and Henrik was last seen in Ordinary People. Kol, Finn and Henrik are indirectly mentioned by Mikael.This is her final appearance on the show.Mary was last seen in Gather Up the Killers.Mikael was last seen in Night Has A Thousand Eyes.People in the alley - Slaughtered killed by Klaus (under the influence of The Hollow).Raiders in the forest - Slaughtered killed by Mikael (flashback).This episode marks Sebastian Roché's first time onscreen as Mikael through a flashback, as well as an illusion, since his character's death in TO season two episode Night Has A Thousand Eyes.Marcel is captured by the Mikaelsons and trapped in the same spot he had bound Klaus to.The Hollow is now able to manifest as a black incorporeal form with pale glowing blue eyes.Sofya is revealed to be working to kill Klaus, but is angered that Marcel was brought into to it which wasn't part of the deal she had made with a witch.Marcel's blood is used by the Hollow to create thorns capable of killing an Original with one scratch.The Hollow is revealed to have been trapped in an unknown dimension through unknown means and was awakened when Davina destroyed the connection of the Ancestral Plane five years earlier.Mikael for the former and Elijah for the latter. The Hollow used the illusions of someone that is hated or feared to manipulate Klaus and Marcel.She tells Mary that she believes that it's not through the Labonair family and she believes it wants to finish the job by killing her and Hope. Hayley realizes that The Hollow, for some reason, has targeted the Labonair family over the centuries, including using Jackson's grandfather to murder her parents.Freya has created a weapon other than a White Oak Stake to kill Marcel, an Upgraded Original Vampire.This is the first episode of the season in which Vincent does not appear.

Aiden Flowers as Young Klaus (flashback).Sebastian Roché as Mikael (flashback)/ The Hollow.Riley Voelkel as Freya Mikaelson/ The Hollow.Yusuf Gatewood as Vincent Griffith (credit only).Phoebe Tonkin as Hayley Marshall-Kenner.Daniel Gillies as Elijah Mikaelson/ The Hollow.Joseph Morgan as Niklaus Mikaelson/ The Hollow.

I hear you knocking