Kevin (Justin Theroux) seems to be losing his mind on the next episode of "The Leftovers" season 3.

In the trailer for the episode called "G'Day Melbourne," Justin appears to be on the brink of losing his sanity once again as he gets disturbed by some mysterious visions that he cannot explain.

The trailer begins with a conversation between Kevin and Nora (Carrie Coon), where she reassures him that he can tell her all his problems. However, Kevin tells her that he cannot speak about it.

On the other hand, the synopsis of the episode also reveals that he and Nora will venture on a trip to Australia where she will be on a trail to track down the leaders of a very elaborate scam. Meanwhile, Kevin is sidetracked on their mission when he is caught off guard when he sees someone from his past. This pushes him to face the traumatic events that he experienced three years ago.

However, the trailer does not reveal who the mystery person is from Kevin's past who is out to haunt him in the present times.

During an interview with HBO, series co-creator Tom Perrotta talked about Kevin's upcoming struggles in the third and final season of the psychological fantasy thriller.

"To me, Kevin is somebody who's trying to guard and uphold the social order that exists, which is under threat," Perrotta stated. He also offered a hint about what the character will have to go through for his upcoming mission in season 3. "So there's that overt mission. The subterranean mission is whether he's going to go crazy doing it because the stresses on him are enormous. Can Kevin preserve the order of the town and remain sane while doing it are the through lines of the show."

HBO will air the next episode of "The Leftovers" season 3 on Sunday, May 7, at 9 p.m. EDT.