You have to give Trespassers exactly thirty-three minutes. The film sets up the elements of a home invasion story, and for that length of time, it appears as though it's going to adhere staunchly to the playbook. Then, right after the half-hour mark, the first thing happens that's genuinely surprising. From there, it becomes a slick and suspenseful, albeit a tad shallow, thriller with several twists that catch you off-guard.

Two couples rent a luxurious home in the desert for a weekend getaway. Sarah (Angela Trimbur) and Joseph (Zach Avery) are struggling to deal with a recent miscarriage. Estelle (Janel Parrish) is afraid to leave the abusive Victor (Jonathan Howard). As their issues play out late one night, a stranger, credited only as The Visitor (Fairuza Balk), knocks on the door. She claims her car broke down and she needs to use the phone. Once inside, she keeps coming up with lame excuses not to leave. Nothing else should be revealed, other than that there is, in fact, a home invasion that leads to several moments of gruesome violence.

Trespassers has an admirable willingness to examine how people react in stressful situations. Sarah lets The Visitor in, against the wishes of Victor. Almost immediately, everyone begins feeling uncomfortable. Does she have some malevolent intent, or is she just a bit flaky? As the evening wears on, Victor becomes more freaked out, loading himself up on cocaine. Joseph tries to defuse the situation. Although overt things do occur, the film builds tension by emphasizing the dynamics between the core group as much as it does the actions of the intruders.

When it does focus on the outwardly scary stuff, Trespassers delivers some decent jolts. Director Orson Oblowitz provides the movie with a tight pace and a visual style that makes the house seem creepier the longer things go on. One of the intruders wears a lucha libre mask; the way he's photographed – as a hulking beast looming over his victims – makes him even legitimately threatening.

The one element Trespassers really needs is a more developed reason why the intruders break in. What's here is too simple, and the implications of it aren't examined in much detail. That ultimately hurts the picture somewhat, because the reason for the intrusion is essentially a MacGuffin. The plot would have much more impact if we knew precisely what Sarah and the gang have unwittingly found themselves in the middle of. Similarly, the way The Visitor ties into everything isn't entirely satisfying, despite Balk's terrific performance.

Trespassers is available on VOD at the same time that it's in select theaters. Because of those not-inconsiderable flaws, I would recommend it more as a VOD rental, where you're only paying a couple of bucks. There are enough intense moments to keep you hooked in this lean-and-mean picture. Just don't expect the plot to make a whole lot of sense.

out of four

Trespassers is unrated, but contains adult language, sexuality, drug use, and graphic violence. The running time is 1 hour and 28 minutes.