Barbara Stanwyck as Phyllis Dietrichson Comments

When Walter Neff (Fred MacMurray), a bright insurance
peddler, meets Phyllis, can't he see that she plans to use
his sexual avidity to get him to kill her cranky, unloving
husband and then take the rap for the crime? Can't he sniff
out the sulfur under her perfume? Of course not, because the
type hardly existed in Hollywood films before. This Billy
Wilder–Raymond Chandler adaptation of a James M. Cain
novel ushered in the film noir era of duplicitous dames and
the dupes who fell for them. Phyllis found her perfect
embodiment in Stanwyck, maybe the movies' all-time smartest
actress (street-smart, anyway). This killer doesn't kid
herself; she knows what she is. At the end, just before
plugging her accomplice in the chest, she confesses, "I
never loved you, Walter, you or anybody else. I'm rotten to
the heart." Rotten, ripe and irresistible.