Superhost. Shudder, 84 minutes. Three stars
We've all met people who creep us out for reasons we can't quite explain. There might seem to be no rational justification, but they just seem a little ... off. Sometimes this turns out to be unfair, sometimes it turns out to be right, but it's happened to all of us. And if it hasn't, look in a mirror: other people might be thinking it about you.
Of course, this socially awkward situation doesn't usually escalate to the point of violence, but it can and often does in horror movies.
Travel vloggers Claire (Sara Canning) and Teddy (Osric Chau) are struggling with their Superhost site, where they document their travels and stays. Hits and subscriber numbers and thus income are down and they're relying on parental aid.
Teddy is more sanguine about things than Claire, perhaps because, as he secretly relates to online viewers, he's got an engagement ring and is planning to pop the question to his partner.
The opportunity to do so might arise on their next stay, which thus assumes a double significance: will it be the place to turn things around for them both professionally and personally?
Claire and Teddy arrive at the remote woodland home - a striking, apparently real, place with lots of big windows - and find the code they've been given doesn't work. Not to worry, though: their host Rebecca (Gracie Gillam) soon turns up, super-perky and helpful and eager - very eager - for an excellent review.
Mobile and internet reception is poor and Rebecca is smothering in her desire to ingratiate herself but the couple decide to settle in to their new experience and see how it goes.
As any horror fan could tell you: it gets worse - much, much worse.
Writer-director Brandon Christensen's Superhost could have been just another entry in the wildly uneven "X from Hell" horror subgenre, with a 21st-century twist.
But it's a pleasant surprise: a tight, economical, well-acted piece with decent characterisation, good actors, and well-used settings.
Christensen makes good use of simple but effective devices - shadowy figures, mysterious noises in the dark - and builds the suspense skillfully as the vloggers discover more and more disquieting things about the house and its host.
There's a small but important role for seasoned daytime soap star Barbara Crampton and the three leads all have extensive lists of respectable credits (and all three worked on Supernatural).
Canning captures Claire's seriousness and frustration well and Chau plays off her nicely as the more upbeat Teddy.
But the scene-stealing role, of course, belongs to Gillam whose character is reminiscent of "number one fan" Annie Wilkes in Misery.
She moves believably from someone who had an overeager desire to please to a discomfiting presence whose behaviour is sometimes jarring (when being interviewed, she emits a loud scream before beginning to talk) to insane, murderous rage. It's a performance that stops just on the right side of histrionic camp.
The characters' sense of unease is believable and so is the way the tension builds. There's not a lot of violence, but it's very effective when it comes.
The vlogger element is effectively incorporated into the story. We've all seen and heard the annoyingly heightened enthusiasm of people broadcasting on platforms like YouTube.
Here we're shown some of the desperation that might lurk behind that forced cheerfulness and reminded that the fervent desire for clicks and followers can drive people to some disturbing behaviour.
The cruelty and callousness that can arise out of being a semi-anonymous part of the online world - on both sides of the screen - is also conveyed.
If the second half suffers a bit from credulity problems - the all-too-common "Why did they DO that?" questions - and the film is not a major piece of work, it's still fun, and the ending is effective and apt.
Superhost is an above-average horror flick and well worth a look.