"Berserk" opens with Rhys Wakefield's down-on-his-luck and agentless protagonist, Evan, who is on his way to Raffy Rivers' Hollywood Hills home to finish the zombie script they've been working on for two years. As Evan and Raffy are rehearsing a scene from their script, Evan comes to the realization that they have never fully experienced "true animalistic fear" in their entire lives, and therefore are unable to effectively feel what their characters are going through. After Raffy convinces Evan to smoke some weed and take shrooms to begin their trippy journey, Evan becomes paranoid, confusing reality with delusional images. The friends agree to do some crazy things to feel the fear that they've been missing out on, and the drugs only heighten these acts of immersing themselves in purely fear-based behaviors. With magic mushrooms in his bloodstream, Evan all-out hallucinates.

After Raffy pulls a mean prank on Evan involving one of their other celebrity friends, Huntley Thomas (Jack Falahee), the story starts to really spin out of control. Evan encounters what turns out to be Huntley wearing a ski mask running out of the front door of the house with his computer. Thinking that it's one of Raffy's crazy stalkers, Evan throws a hammer at the back of the culprit's head. But he soon discovers it's not a stalker, but their friend, Huntley, who is now dead. Shortly after they bring Huntley's body inside and figure out what to do, somebody from Raffy's past shows up out of the blue.