Dylan O’Brien is haunted by the past in the Flashback trailer

Frederick Fitzell (Dylan O’Brien) is living his best life – until he starts having horrific visions of Cindy (Maika Monroe), a girl who vanished in high school. He reaches out to old friends with whom he used to take a mystery drug called Mercury, but realizes the only solution lies deep within his own memories. So Frederick goes on a terrifying mental odyssey to learn the truth.

Directed by Christopher MacBride, the film stars Dylan O’Brien, Maika Monroe, Keir Gilchrist, Hannah Gross, Emory Cohen, Amanda Brugel, and Aaron Poole.

Flashback is released on 4th June 2021.