The episode is called “Voodoo In My Blood” and here’s how The CW describes it:
THE VAMPIRE DIARIES’ MATT DAVIS GUEST STARS – After being summoned by the ancestors, Hayley (Phoebe Tonkin) and Klaus (Joseph Morgan) travel to the ancestral world and come face to face with Davina (guest star Danielle Campbell), Klaus’ former foe and the one person who holds the secrets to The Hollow’s demise. Meanwhile, old wounds are re-opened when Elijah (Daniel Gillies) and Marcel (Charles Michael Davis) are forced into an uneasy alliance. Together, they meet with Alaric (guest star Matt Davis) who has tracked down a crucial artifact that could help in their fight against The Hollow. John Hyams directed the episode written by Talicia Raggs & Christopher Hollier (#408). Original airdate 5/12/2017.
UPDATE: Some photos can now be found below!