There is not going to be any suspense in this review, I will tell you right off the bat that this was a disappointment. It should not have been, but the writing, which is so good in the first act, falls off in quality and logic in the third act, and like so many horror films, it is the payoff that screws up the film. The slow burn opening gets wasted by a series of non-sensical events at the end. I just saw "See How They Run" and the director in that story wanted to rewrite the ending of Agatha Christie's "The Mousetrap". There is a scene in that movie where a series of storyboards shows the direction he wanted to take. The makers of this movie must have a similar set of storyboards from the same trite minds that think all horror films have to end the same way.
What is so promising at the start of the first section, gets added too in a second section, where it looks like we might be going into a different kind of barbaric act, featuring a non-horror situation. The character played by Justin Long, is getting a Hollywood cancellation moment, and it looks at first as if it is going to take a unique perspective on that circumstance. The financial and professional ruin of an actor on the brink of sitcom stardom, is the event that drives this character into the scenario we saw played out at the start of the movie. Sadly, it is not to be that an injustice is giving sympathy to a potential victim. Instead, the movie plays this storyline out as a comeuppance. So again what was unique and potentially intriguing gets washed away in an act of woke contrition.
Technically, the horror elements that are visualized are done quite well. There are a couple of jump scares and some mild gore to establish the violence bona fides of the film. It is not the acts of violence and mayhem that are the most horrifying moments however. There are three standout visual images that will really haunt you, if anything from the movie does. In a flashback sequence, we see the machinations of a serial killer/rapist/kidnapper. The point of view from behind him as he shops for products to facilitate his actions is disturbing. When we see the casual way that he gains entry into a future victim's home, it is a terrifying moment that should make every homeowner pause. This whole sequence takes place as we enter the final act. The second visual stunner is the discovery of a room, equipped with a filthy bed and a couple of other items that will induce nightmares without thinking too hard. It is this visage that startles out main protagonist Tess, into the actions that any human being would have, Fight or Flight. Unfortunately, the character has to do the stupid thing that every fan of horror films screams at the screen about, "Don't Do it!", and then she does. In my view however, the most disturbing visual moment takes place in daylight, outdoors, while Tess is in the car driving away from the site of the action. Block after block of abandoned, dilapidated houses roll past her windows. She has stayed in a vacant warzone for a night, and she is lucky to be alive. So once again, living down to the trope of the most basic horror film, what stupid thing does she do? That's right, she goes back to that neighborhood, after being warned, with the plan to spend another night there. 
Georgina Campbell is Tess, who is so smart, alert and wise on that first night. Her spider-senses tingle and she takes appropriate action, until it is time for her to do something, she herself has said not to do. Last summer there was a horror film based on a single word that every person in a frightening situation ignores "Nope". She literally says it out loud, and within two minutes does it anyway. Bill Skarsgård plays a sympathetic red herring. We are supposed to be suspicious of him but we get won over. His character goes from solicitous with Tess to dismissive for no good reason other than to make us doubt him, but it was inconsistent with the way the character had been presented in the slow burn. AJ, the Justin Long character can be forgiven his stupidity at first, he is distracted, but if he is engaged enough to complain on the phone to the worst property manager in the Detroit area, you would think he could pick up the bad vibes in the house location immediately. So basically, the three main characters are too stupid to avoid the risk right in front of them with the flashing yellow sign.
Finally in the climax, like all horror films, the monster is indestructible, and we are also asked to sympathize at the same time that murder is going on in front of our eyes. Horror films need to start working backwards. Figure out your ending before to write the opening. When you expend all the energy and creativity on the set up, whatever you have left gets used on the payoff, and it isn't enough. There was a lot to like about the movie, but all that is gold gets cancelled by acts of stupidity, improbability, out right cliché, and the impossible. Catch it on shudder next month.
