Writer-director Shane Atkinson’s “LaRoy, Texas” is a deliciously nasty film in the style of early-John Dahl (especially his “Red Rock West”), with the grim humor of the Coen Brothers thrown in. This is the kind of southern pulp noir that grabs its audience by the hair and forces them down in the muck.

John Magaro is Ray is the definition of a pushover and a classic noir schlub; his older brother, Junior (Matthew Del Negro), treats him like his inferior even though the two supposedly own equal shares in the hardware business they inherited from their parents. Ray also learns that his wife, Stacy-Lynn (Megan Stevenson), is having an affair.

This revelation is delivered to him by a man named Skip (Steve Zahn), a low-rent private detective good ol’ boy whose attire is a bolo tie and black cowboy hat that (for him) completes his wannabe badass look. Never earning respect from anyone he encounters, the local police and the rest of the town see Skip as more of a bumbling intruder than a Texas-bred Phillip Marlowe.

Sitting outside the sleazy motel where his wife has her trysts, Ray decides to shoot himself. As he puts the gun to his head, along comes a strange man who pulls up next to his car. The stranger mistakes Ray for a hitman. As he gets in the car, the man hands Ray money and tells him, “It needs to be done tomorrow.” So begins Ray’s twisted and increasingly bloody path to his fate. As it comes to pass for the young man in way over his head, suicide may have been the safer bet.

Everyone in this town is morally corrupt, or, just plain misguided. Strangely enough, the one character with a focused sense of self is Dylan Baker’s Harry, the hitman whose job Ray took on that fateful night. Always one of our most interesting character actors, Baker plays Harry as a man who respects commitment while presenting himself as a milquetoast. Baker is precise in crafting this very real wolf in sheep’s clothing, turning in one of his best performances since Todd Solondz’s button-pushing 1998 film “Happiness.”

This is an immersive crime thriller with a sharp edge. Atkinson’s script has a lot going on but keeps things tight and doesn’t lose the dramatic (and occasionally comedic) threads of the plot or its characters. The director doesn’t let the film get too absurd (save for a couple of cops who constantly hound Skip) and won’t allow himself to skate by being a mere tribute. Atkinson cuts a clear and entertaining path through this darkly comic narrative by giving certain characters an inner light. While everyone is imbued by ‘the devilish,’ a few are inherently good people just caught in bad situations.

Two of the most interesting characters are LeDoux (Adam Leland) and his wife Midge (Darcy Shean). Leland is great as an intimidating used-car salesman. While this boisterous man carries a gun and tough-talks Ray and Skip, his deceptively obedient wife reveals herself to be the one who controls the town. As their characters expertly represent the mystery of everyone who crosses paths in the town, no one is what they seem.

Shane Atkinson proves himself a confident filmmaker and a screenwriter with an ear for dialogue and skill in designing interesting characters and situations. Armed with a dedication to character and atmosphere, “LaRoy, Texas” is an intense and involving southern-fried noir.