Low budget film noir about an unfaithful wife (Helen Walker) who schemes have her rich husband (Brian Donlevy) murdered during a car journey. When her lover/accomplice fails to complete the kill and is consumed in the flames of a crash with a petrol truck, everyone assumes it is Donlevy's burned corpse at the scene of the accident.
While the concussed, amnesiac husband stumbles into a small town in Idaho to work as a mechanic for the tomboyish Ella Raines, Walker is busted by a smart Irish cop (Charles Coburn) and goes on trial for a murder that never happened.
Impact shows how robust the conventions of film noir are. The film is a reshuffling of noir archetypes, made by an unremarkable director and crew with a B standard cast. But it's still a very entertaining film, with a strong atmosphere.
Donlevy is fine as a schmuck that gets played for a sap, and Raines lifts the second half as the down to earth good girl who contrasts with Walker's glamorous femme fatale. Arthur Lubin was a lifelong low budget director but he could turn out a pacy thriller and he handles the narrative well. American film noir rarely lets you down.