The premise for Blood Red Sky sounds like it was generated by Netflix’s recommendation algorithm—or a producer throwing darts at random plot elements from horror and thriller films. Director and co-screenwriter Peter Thorwarth must know the premise is ridiculous, but to his credit, he attempts to take it seriously and play it out in ways that are both intriguing and intense. There are so many storylines to resolve, plus an overabundance of backstory, that sometimes it unfolds as if Thorwarth is directing traffic instead of scaring us. Still, in between all that bloat is a vicious movie that is willing to go berserk like its bizarre, tortured hero.

Nadja (Peri Baumeister) is about to board a transatlantic flight with Elias (Carl Anton Koch), her precious moppet son. The purpose of the flight is a mysterious medical treatment, and indeed Nadja is on edge because of her undefined condition. Everything goes smoothly, more or less, until hijackers take over the flight. The hijackers include the crew and copilot, so they have no problem seizing control. Little do they know, however, that Nadja’s malady is that she is a vampire, one who has mostly been able to keep her nature at bay. As the hijackers threaten the crew and divert the flight, Nadja has no choice but to transform into a full-on monster, taking out the hijackers one by one. That comes with its own problems, and soon enough the entire flight turns into an outbreak of fangs and supernatural bloodlust.

A vampire on a plane is enough plot for one movie, so the hijacking is how Blood Red Sky ups the ante, and Thorwarth doesn’t stop there. There is a subplot involving a passenger serving as a father-figure for Elias. There is bickering among the hijackers themselves because one of them (Alexander Scheer) also happens to be a homicidal maniac. The solution to all this plot is for Thorwarth to rely on swift, easy characterization. That’s a common technique for a film like this, since we need to know who to trust in a contained environment like an airplane. But he runs into trouble when he moves the story away from the hijacking. There are several tedious flashbacks that tell the origin story of how Nadja becomes a vampire and comes to understand her nature, plus a frame narrative: Blood Red Sky begins with a flash-forward where we see the plane land on a military-controlled airfield, and the climax resolves that story. Each time Thorwarth cuts away from the cabin is another place where he undermines the lunacy of its premise.

Vampires are fun creatures to explore because they retain some intelligence, yet cannot help but follow their evil natures. Blood Red Sky takes that idea and deepens it, turning vampirism into a metaphor for maternal instinct. Elias is so precious that Nadja feels justified when she kills to protect him. What’s fun about this metaphor is how it mutates once more passengers also become vampires. Soon, the film becomes an exploration of our animalistic nature, and then it escalates into full-on biological panic. It is impressive how Thorwarth transforms the tension and ideas within the setting, and to his credit, he puts his characters into situations where they have to make impossible choices in seconds. Between that and the copious violence, parts of the film are bloody fun.

Thorwarth has written and directed many films in German, and Blood Red Sky has the formal rigor of a journeyman filmmaker. He shoots in a dark grey palette, and does an impressive job of juggling where the characters are in relation to each other. An early death shows he has no problem with bloody spatter, and by the time conditions on the plane get really bad, he shoots in a frenzied way that matches the terror of the passengers. Another impressive feat is how he balances the languages in a multinational cast. This is where Blood Red Sky finds a hint of realism: the dialogue jumps between English and German with English subtitles, but this is never confusing and all the characters’ language skills are plausible.

Blood Red Sky is a film that is suited to Netflix. You can tell exactly when it will drag, which is a perfect opportunity to grab a snack or take a bathroom break. The exciting portions are well-telegraphed, so you know when the film will require your complete attention. That quality is both an asset and a problem. Sitting in a dark theater would make its flaws all the more apparent. But when it explores its admittedly bloated conceit, there’s enough technical skill and strong acting to appease the half-bored home viewer. This is a film that delivers on its premise, so your enjoyment hinges on whether “hijackers take over a plane, and vampire mom is on board” sounds like great trash or irredeemable nonsense.

Blood Red Sky opens on Netflix on July 23.