Director Chloe Okuno has given the well-worn genre of the stalker film a subtle shock of originality with her feature debut, Watcher. She has made the film less about the violence, which is more implied than seen, and more about the act of watching itself.

As a result, Okuno has created a thriller in which the temperature is kept at a comfortable simmer for the majority of its running duration until the final few minutes, when the heat is turned up to a realistically high level. A film that maintains a strong ambiance of dread simply by having someone look out the window and go grocery shopping is refreshing in a genre movie climate characterized by cheap thrills and easy scares — whatever keeps us from clicking on something else — is a welcome sight in a genre movie climate.

To be sure, Watcher is set in modern-day Bucharest, which is meant to appear scarier than most cities (a Dracula souvenir reminds us of Romania’s history as a hotbed of horror). The underlying source of terror, however, is the loneliness and isolation of an expat, Julie (Maika Monroe), who has followed her boyfriend Francis (Karl Glusman) to a foreign country for his new work in a foreign country.

Julie’s mind begins to wander when she notices a man staring at her from a window across the street, especially when she notices a man repeatedly staring at her from a window across the street — we learn that Julie used to be an actress; she appears to have no new career plans — and she begins to let her mind wander. Julie is certain that the man is a stalker almost as quickly as you can say voyeur, and her suspicions are reinforced when he follows her into a supermarket one day. The fact that there is a serial killer on the run in town, one who preys on young ladies, only adds to her sense of unease about the situation.

By now, most films would have ratcheted up the action by switching to either race against the clock mode or torture-porn mode, depending on the genre. Yet another strategy is employed by director Okuno and screenwriter Zack Ford: they strive for as much authenticity and ambiguity as possible, placing us in Julie’s shoes as we witness what she witnesses and suspect what Julie suspects. All of us enjoy making up stories in our thoughts, and Watcher, like the best point-of-view thrillers, makes that habit its primary occupation: we’re watching someone watching someone else watching someone else watching being watched.

Rather than immediately contradicting Julie, Francis tries his best to work around her inclinations. Eventually, the police are called in to help, and they manage to bring Julie face to face with her stalker (Burn Gorman, arguably one of the creepiest looking actors alive). After the dust has settled, we begin to question if Julie is imagining things or if she is simply bored to death, a thought that Francis expresses aloud as the air is cleared.

With a good subtext exploring the listlessness of being an expat partner, Watcher is similar to Lost in Translation, but with the Bill Murray role being replaced by a perhaps psychopath. The film doesn’t completely avoid stereotypes about its setting — the only neighbor Julie befriends is a stripper who works in a club that screams post-communist despair — but it does a good job of portraying the loneliness of a person who has moved abroad and is unable to fit in or communicate with others.

Let’s just say that Okuno does a wonderful job of keeping us in the dark and wondering about Julie’s sanity until her film’s nail-biting ending, which is brief, disturbing, and delivers the gore we’ve all been waiting for: With the slow and steady buildup and Monroe’s ability to consistently appear terrified without batting an eyelid — something she also demonstrated in David Robert Mitchell’s It Follows, this is an ending that seems well-deserved.

Watcher, as a debut feature, is expertly and economically realized, making the most of what is available: one flat, two windows, a few streets, and a misplaced cat, to name a few elements. Okuno and cinematographer Benjamin Kirk Nielsen construct each sequence to have the most possible impact, even if there isn’t much occurring other than someone glancing out the window at times. However, they are successful in making us appear as well, as they wait for things to go wrong and for our promises to be fulfilled.