I’m still working my way through my renter’s collection of old mystery movies, and this weekend I was pleasantly impressed by a fairly obscure 1949 production called “Impact,” starring Brian Donlevy.

“Impact” is technically classed as Film Noir, but in honesty it must be about the least noirish Noir film ever made. Instead of the angular shadows and cramped urban settings we expect in Noir, this film is largely set in the sunny outdoors and bright interiors. More importantly, instead of the fatalism and cynicism so characteristic of the form, this movie is about redemption and mercy. As a matter of fact, this one is so saturated with Christian values that you almost expect to see World Wide Pictures in the credits.

Donlevy plays Walter Williams, the head of engineering for a major corporation. At work he’s an alpha male, aggressive, savvy and a risk-taker.

But at home, in the company of his young, beautiful wife, Irene (played by Helen Walker [no relation]) he’s a pussycat. He defers to her, spoils her, and actually simpers in her presence. (By the way, this movie made me revise upward my estimation of Donlevy as an actor. I always had a hard time buying him as a tough guy. He struck me as a shrimp with an attitude, all swagger and no punch, especially when cast as a heavy against tall guys like Joel McCrae and Gary Cooper. But here he’s given other things to do than strut around trying to be intimidating, and he does a very creditable job in the vulnerable scenes). Irene bestows on him the nickname “Softy,” and he thinks it’s an endearment (I know what that suggests, I wouldn’t be surprised if the writers intended it, but this was 1949, when Hollywood still understood subtlety).

So poor Walter hasn’t the least suspicion when Irene suddenly begs off accompanying him on a road trip to Denver on business. Instead she asks him to give a lift to her “cousin.” The cousin is actually her lover, a man named Jim Torrance, and he and Irene have worked out a plan for him to murder Walter on the way and make it look like an accident.

But fate intervenes. Jim fails to finish Walter off, and then is himself killed in a fiery crash. The charred remains in Walter’s car are assumed to be his.

Hitching a ride in a passing moving van after regaining consciousness, Walter soon figures out, through newspaper stories and a couple strategic phone calls, that he’s been betrayed in the worst possible way. When he reads in the papers that his wife has been arrested for his murder, he figures it would be both just and satisfying to let the law take its course. So he hits the road.

Soon he fetches up in the pretty town of Larkspur, Idaho, where he gets a job as a mechanic at a gas station owned by the fetching Marsha Peters (Ella Raines). And it’s here that simple, small town (Christian) virtues begin to wear away at his anger and bitterness. Two significant scenes involve Walter’s first evening as a boarder with Marsha and her mother (where he reaches for the food, only to discover that they’ve bowed their heads to say grace. Imagine that happening in a movie today), and a Sunday church service (after which Walter breaks down and tells Marsha his true story).

Walter’s difficult (also well-scripted and acted) decision to do the right thing plunges him into the final conflict of the film, in which he finds himself on trial for his own life. His only hope is Marsha’s (and a cop’s, played by the old, reliable character actor Charles Coburn, who keeps forgetting to keep up his Irish accent) faith in him and determination to prove his innocence.

A preachy, spoken introduction and epilogue are a weakness in the story, but they used to do that sort of thing a lot in those days.

Rent “Impact” if you get the chance. I think you’ll like it.