Vampires don’t typically vomit the blood they’ve just sucked. That, therefore, is one of the big clues that The Transfiguration’s teenage protagonist, Milo (Eric Ruffin), isn’t really the pipsqueak Nosferatu he appears to be while slurping at the neck of a dead guy in a restroom stall. He also steals the victim’s cash, an opportunity that Bram Stoker didn’t seem to consider.

Yet it takes a while to suss out exactly what’s going on in writer-director Michael O’Shea’s first film. Milo walks in daylight and has a reflection. He watches graphic predator videos and has a stack of VHS tapes of movies such as The Lost Boys and Fright Night. In class, he works on “The Rules” instead of taking notes. But he’s a little too attracted to blood—with a terrific low, rumbling soundtrack indicating when he’s got a donor in sight—for a viewer to assuredly grasp that Milo’s just playing. (If you are sure, you probably read the synopsis, which otherwise doesn’t fit the film at all.)

Both Milo and The Transfiguration as a whole are moody and quiet. Milo lives with his older brother, Lewis (Aaron Clifton Moten), because their parents are dead. But Lewis barely acknowledges Milo, forever on the couch watching TV while Milo stays in his room. Kids at school think he’s weird; the gang that hangs outside of his building call him “freak.” So it’s not until he meets another outcast, Sophie (Chloe Levine), that he says anything of substance.

Sophie quickly falls for Milo, but the reason is anyone’s guess. He never so much as cracks a smile in her presence; in fact, on the night they meet, O’Shea stages the scene to indicate that Milo’s going to kill her. And all he talks about is vampires, frequently using the word “realistic” to judge their portrayal in any given fictional work. (Twilight, needless to say, is not realistic: “I mean, vampires don’t twinkle,” he tells Sophie.)

Another contrived aspect of the story involves Milo’s daydreaming. Muted tones color these scenes, which involve the boy staring at, say, his brother’s bed or his girlfriend’s neck while imagining bloodshed. Eventually he—and the film—are snapped back to reality when someone asks what the hell he’s doing. You’d think he’d be wise enough to fantasize in private like a normal teenager.

Buy into these machinations, however, and The Transfiguration is a fairly absorbing, albeit low-key, horror debut. Milo remains inscrutable throughout; Ruffin lends the character an impressive weight, especially considering that he’s in almost every frame. Sophie learns to accept Milo’s obsession—though he freaks her out a couple of times—and soon both are turning to vampire lore as well as each other to soothe family wounds. (She’s an ironic choice as Milo’s girlfriend, considering she’s a cutter.)

As the film comes to a close, it initially doesn’t seem as if the story had any arc, nor that Milo had at all changed (in a human sense, of course). But he does, in fact, do an about-face regarding his hobby, leading to a shocking and solemn end. A folk song accompanying the credits completely ruins the mood, but like the story’s other hiccups, it’s not enough to suck the lifeblood of the film overall.

The Transfiguration opens today at the Angelika Pop-Up.