In Janney’s capable hands, our heroine is fully fleshed out, yet lean with more gristle on the bone than meat. She delivers zingy one-liners as well as she does a knock-out punch. Her refreshing spin on this archetype, blending masculine bravado and bluster with feminine wit and wisdom, elevates the spartan material.

The plot races from one tense outdoor confrontation to the next, as “Lou” tells a simple but effective story about two women enduring the harshness of the elements and the machinations of violent men.

The performances are mostly entertaining, the scenery is rich, but it has flaws in the story that make it difficult to accept in some places. It’s also these flaws that allow the audience to figure out the plot a little prematurely.

Though Lou is derivative and schematically plotted, it’s gripping enough to get away with it, thanks largely to Janney’s committed performance.

Sometimes you just want a crazy action movie to kill an evening, and “Lou” fits that bill. Just don’t expect to be thinking about it tomorrow.