Archie (KJ Apa) turns dark in "Riverdale" season 2 after his father died in his arms. Meawhile, Ross Butler reveals why he exited "Riverdale."

"Riverdale" returns next year with season 2 with big changes among the main characters of the series, especially with Archie, Veronica (Camila Mendes), Betty (Lili Reinhart), and Jughead (Cole Sprouse).

Previously in "Riverdale," Fred Andrews (Luke Perry) died in the arms of his son, and according to executive producer Roberto Aguirre-Sacasa, it will be the biggest catalyst in Archie's life.

"It's like the moment when Bruce Wayne sees his parents gunned down in Crime Alley or when Peter Parker learns that that his Uncle Ben was murdered by a burglar. It absolutely changes Archie and sends him on his season-long journey, which — without giving too much away — starts in a really dark place: revenge," the showrunner explains to The Hollywood Reporter.

Aguirre-Sacasa adds that Archie will still find his way back into the light, with his storyline being the "spine" for the whole season 2 of "Riverdale."

Aside from Archie, Jughead will also have an unexpected turn in his life.

Jughead has chosen to move into the other side of town and join the Southside Serpents, and it appears he has found where he belongs. However, this might not sit well with Betty and their relationship.

"There's a chance Jughead will be trying to live a double life, one with Betty and one with the Serpents," Aguire-Sacasa shares.

But the showrunner confirms that Jughead moving to the Southside has a key role to play in the big divide between the two sides of town.

Meanwhile, Butler has left "Riverdale" and his role of Reggie Mantle, and the actor shares with Seventeen why.

Butler admits it is because of conflict of schedule, and that he chose to prioritize "13 Reasons Why" over "Riverdale." Since the producers could not adjust to Butler's schedule, they had to recast the character.

"Riverdale" season 2 is anticipated to return next year on The CW.