This is Mike Flanagan’s first adaptation of a Stephen King novel (the second is Doctor Sleep, which is not currently on Netflix) and a truly horror-filled movie. Until Mike adapted it, many people considered it largely impossible to adapt into film because of all the inner demons it grapples with.
It’s about a woman who is handcuffed to a bed with no way out after her husband suddenly passes away from a heart attack. It's a survival story in the midst of a potential killer, and even Stephen King called it “hypnotic, horrifying, and terrific.”