I bought this, unseen, because Jessica Chastain was in it. I think she's a terrific actress, and more importantly, she's selected roles in projects that are respectable and thought provoking. This movie, however, was a real dud. She and the other actors did a fine enough job but the standard cookie cutter storyline that Hollywood relies on for most horror films couldn't sustain my interest - which is a shame, because an intriguing premise was, once again, ruined by lazy writing.
Expect tons of boring "startle" moments with predictable suspense music in the background. Expect some reeeeaaaal slow movements, to artificially build suspense (typical reactions to unknown situations are freeze, fight, or flight - not acting as if you're moving through a vat of molasses).
If you're looking for good horror films that will make you think, check out Hereditary, Midsommar, Rosemary's Baby, Suspiria (new version - sorry Dario, it's better), The Lodge, Killing of a Sacred Deer, The Shining.
I wondered if perhaps i was being too harsh by giving this movie only one star -after all, it has very good production values, good acting, good cast, good effects - but then i realized that "good" isn't good enough anymore. The amount of money spent on a movie does not correlate to its quality. This movie left no lasting impact on me. If i forget about it the minute it ends, then that really says it all.