Smitten insurance man Walter Neff (Fred MacMurray) plots the perfect murder with femme fatale client Phyllis Dietrichson (Barbara Stanwyck): staging her husband's "accidental" death to collect double indemnity on his life insurance and absconding with the loot. But before their scheme can pay off, the lethal duo must first get past a crafty claims investigator (Edward G. Robinson) who senses something isn't kosher.