A picture of Stephen Amell as Oliver Queen from the TV series "Arrow." Facebook/ Arrow

Executive Producer Wendy Mericle has teased in a recent interview that the flashbacks in “Arrow” Season 5 will be “dark” and “gritty.” There will be a heavy focus on the Russian mafia and the Bratva this time around.

[Spoiler alert]

In an interview with TV Line Mericle explained that with Oliver’s (Stephen Amell) back story involving the Bratva they wanted to do something “gritty” and “dark,” in order to make it feel “very real.” She said the Bratva is a “pretty interesting and messed-up institution.”

The creative team apparently had to do some research in order to make sure they get it right. Everyone on the staff was required to watch the 2007 flick “Eastern Promises.” Mericle personally watched documentaries about Bratva and “how they operate in Russian prisons.”

The new criminal element that Oliver has to fight this time around is the Mob. The main villain is a character named Prometheus. The character is someone who is out for revenge and has spent the last few years plotting and planning.

However, Prometheus will not be the only villain in “Arrow” Season 5. Dolph Lundgren has joined the cast to play the role of a villainous character who will be seen in the flashbacks.

Mericle teased that Lundgren’s character on the show is a “government strongman.” The producer described the character as being “scary and formidable.” The character apparently had a role in some of the things that happened with Taiana’s (Elysia Rotaru) family in the previous season.

“Arrow” Season 5 is set to premiere on Oct. 5. The title of the first episode is “Legacy.” Oliver’s main task in this season is to train a group of new recruits who join his team. The people of Star City will be inspired after the defeat of Damien Darhk (Neal McDonough) and this leads to vigilantes popping up across the city.