A lot of thrillers begin with or feature a prison-bus break-out as a signature scene — “48 Hrs.” and “The Fugitive,” for instance. But here’s one that’s all about the break-out, or break-in depending on your point of view.

“Below Zero (Bajocero)” is a simple, brutal and harrowing Spanish thriller about an assault on a prison transport bus outbound from Cuenca in the harsh Spanish winter. Director and co-writer Lluís Quílez (“Out of the Dark”) throws misdirection plays at us that bely its simplicity and reliance on basically one location to make an action feature with quirky characters that set up quirkier twists.

That location is the interior of a maximum security prison bus, basically an “armored bunker” on wheels as the driver Martín (Javier Gutiérrez) declares, at one point. He’s a veteran cop on his first “transfer” in a long time.

He’s a family man teamed-up with the brutish Montesinos (Isak Férriz) to haul six dangerous inmates from one prison to another. “Discretion” and “surprise” dictate that they do this in the middle of the night.

But as we see the inmates rounded up to leave, we see one procure a key, and hide it even where a strip search won’t give it away. Ahem.

Montesinos is brusque, no nonsense, inclined to throw his weight around. Martín is the “rules aren’t there to be ‘relaxed'” and “You can’t beat up every dirtbag who gets in your face” stickler.

We’ll see who’s the smarter cop and who’s tougher when the bus is waylaid on a foggy surface road on this longest night of their lives.

The inmates are a colorful crew of varying ages and “types.” The dangerous Romanian human trafficker Mihei (Florin Opritescu) is the one they’re most worried about. Motor-mouthed Gollum (Andrés Gertrúdix) is a nuisance, young Nano (Patrick Criado) has as many tattoos as any of them, aged Pardo (Miquel Gelabert) is in for some major financial crime, tough-as-nails Rei (Édgar Vittorino) simmers in silence, unless you bring up his sister.

And then there’s the cunning and charismatic older con (Luis Callejo), who insists on going by (in Spanish with English subtitles) “my stage name, Ramis.” Like the rest, Ramis promises to be a handful. That’s why each has his own steel-walled cell for the ride.

And then the ride is intercepted. Do we know who pulled this off, “took care” of the escort police cruiser and blew out a tire? Do “they” know who has come to release them, or just one of them, with the possibility the attackers will kill everyone else on board?

After a few seriously illogical moments setting up this backroad hijacking, leaving wounded Martín on his own with six dangerous men, “Below Zero” settles in to a siege filled with surprises.

Callejo, who was Joseph in the Biblical thriller “Risen,” makes a colorful creep who can’t be trusted, even if he’s showing you his hand.

Gutiérrez, a Netflix staple thanks to “Assassin’s Creed,” “The Motive,” “Marshlands” and “The Occupant,” makes a believably over-matched cop who finds the nerve to bluff when his life is on the line.

But as “types,” these characters are all just “Who dies or lies next?” pawns to be played with in the Fernando Navarro and Quílez screenplay, one that considers every way to get into and out of a locked “armored bunker” with whoever’s trying to get at them outside, and a dozen ways to die inside.

It’s no “48 Hrs.” or “Fugitive,” but “Below Zero” is a good one, with or without subtitles.

MPA Rating: TV-MA, graphic violence, profanity,

Cast: Javier Gutiérrez, Isak Férriz, Florin Opritescu, Karra Elejalde, Andrés Gertrúdix, Patrick Criado, Miquel Gelabert, Édgar Vittorino and Luis Callejo

Credits: Directed by Lluís Quílez, script by Fernando Navarro, Lluís Quílez. A Moreno Films release on Netflix.

Running time: 1:46