'Bates Motel' season 5 spoilers: Norman leads a double life after Norma's death; EP teases 'darker' tone for final season

Norma (Vera Farmiga) is still alive in Norman's (Freddie Highmore) mind when A&E's "Bates Motel" returns for its final season tonight.

Season 5 picks up 18 months following Norma's unexpected death. However, not everyone is aware of her passing. Executive producer Kerry Ehrin recently spoke with Entertainment Weekly, and she teased that Norman will have a difficult time accepting his mother's death. Despite his role in her demise, the troubled teen doesn't recognize that Norma is really gone.

"Dylan still doesn't know that Norma has died," Ehrin said. "For the most part, no. It's too painful of an admission to look at. Norman is living in multiple realities and functioning — at the moment." Ehrin also mentioned that this season's tone will be much "darker" than the previous installments. "Because it is so tragic, the dark humor comes out more this season," she teased.

One of the major struggles that Norman will face this season is balancing his public image as the respected owner of Bates Motel and the twisted inner world he shares with Norma.

The series is inspired by the 1960s Alfred Hitchcock film "Psycho," and there will be a lot of references to the film.

In an interview with USA Today, Highmore revealed that fans should look forward to a new dynamic between Norman and his mother. "What's so exciting is discovering a new way of interaction between Norman and his mother, this different character who Vera manages to infuse with the same level of humor and enthusiasm," he stated.

Many characters from Norma's past are also expected to enter the picture. The season opens with Alex Romero (Nestor Carbonell), the sheriff who married Norma before she died, behind bars on perjury charges. Norman's half-brother, Dylan (Max Thierot), his uncle Caleb (Kenny Johnson), and Emma (Olivia Cooke) are coming to town as well.

The fifth and final season of "Bates Motel" airs every Monday night at 10 p.m. EST on A&E.