A small crew of HazMat workers spend a week inside Danvers State Hospital, cleaning out the nasty asbestos so the long-closed building can be converted into offices. As the week wears on, tensions build amongst the men and it seems that the hospital's dark past is about to awaken.
Anderson (along with co-writer Stephen Gevedon) has crafted a slow burn of a movie. There's no denying that the film oozes atmosphere right from the start- it'd be near impossible not to when you're shooting on location in an abandoned mental hospital. Through the use of overlapping timelines, foreshadowing, and extremely creepy voiceovers (courtesy of a series of doctor-patient session reels found in the basement), the film chugs along steadily building toward a surprisingly vicious climax. Anderson doesn't trot out the typical horror film cliches along the way- there's no jump scares, the body count throughout is low- but rather he assumes a patience in the viewer and rewards that patience as the events unfold and secrets are revealed. In other words, this is not a horror flick for the jump cut-ADD crowd.
Aside from the location, the film succeeds largely because of the aforementioned session reels. As Mike (Gevedon) listens to the story of Mary Hobbes unfold on a dusty reel-to-reel in the asylum basement, the warbly sounds of Mary's "alters"- Princess, Billy, and ultimately, Simon- reveal the evil that can lurk within a damaged mind. As Mary's story parallels that of crew chief Gordon (Peter Mullan), we come to understand that there's the possibility that evil can lurk within any of us, waiting for a trigger to be released. Simon personifies that evil for Mary, and when the film closes with this exchange--
Doctor: And where do you live, Simon?
Mary (as Simon): I live in the weak and the wounded...doc.
--it's absolutely chilling.
Where Session 9 falls short, unfortunately, is in the characterization of the crew. They're all damaged men, yet we only get small glimpses into their lives. Learning more about all of them would serve to heighten the tragedy at the film's core. Overall, this is a minor quibble and Session 9 stands up just fine as an atmospheric psychological horror film.