Madison is paralyzed by shocking visions of grisly murders, and her torment worsens as she discovers that these waking dreams are in fact terrifying realities with a mysterious tie to her past.
| Madison Mitchell | Annabelle Wallis |
| Sydney Lake | Maddie Hasson |
| Detective Kekoa Shaw | George Young |
| Detective Regina Moss | Michole Briana White |
| Jeanne | Susanna Thompson |
| Winnie | Ingrid Bisu |
| Jane Doe | Jean Louisa Kelly |
| Derek Mitchell | Jake Abel |
| Dr. Florence Weaver | Jacqueline McKenzie |
| Dr. Victor Fields | Christian Clemenson |
| Dr. Gregory | Amir Aboulela |
| Mendez | Mercedes Colon |
| Officer Rubin | Ruben Pla |
| Officer Lee | Jon Lee Brody |
| Beverly Woods | Paula Marshall |
| Scorpion | Zoë Bell |
| Beta | Shaunte Lynette Johnson |
| Nurse Annie | Natalia Safran |
| Hospital Security Guard #1 | Mike Mendez |
| Hospital Security Guard #2 | Randy Haynie |
| Hospital Security Guard #3 | Cord Walker |
| Research Doctor | Jesus Trujillo |
| Research Orderly | Lisa Catara |
| News Anchor | Danielle Nottingham |
| Gabriel (voice) | Ray Chase |
| Gabriel | Marina Mazepa |
| Young Madison | Mckenna Grace |
| Young Serena | Madison Wolfe |
| Frank | Andy Bean |
| Nurse Velasquez | Patricia Velásquez |
| Mr. Stanley (uncredited) | Patrick Cox |
| Seattle Police Officer (uncredited) | Gregory Garcia |
| Mustang Driver (uncredited) | Emir García |
| Caroline (uncredited) | Renee Harbek |
| Nurse J. De Marco (uncredited) | Janet Hsieh |
| Orderly (uncredited) | Paul Mabon |
| Seattle Police Officer (uncredited) | Gino Montesinos |
| Referee (uncredited) | Josh Rutgers |
| Child Madison (uncredited) | Halston Van Atta |
| Prisoner (uncredited) | Louise Van Veenendaal |
| Seattle Police Officer (uncredited) | Kalina Vanska |
| Prisoner (uncredited) | Christina Veronica |
| Mrs. Ryerson (uncredited) | Rachel Winfree |
