Justice Department agent Alexandra Barnes grows suspicious of the deaths by respiratory failure of several seemingly healthy wealthy men due to a rare condition called Ondine's curse, each married within months to younger wives.

One victim is Manhattan publishing magnate Sam Peterson, whose younger wife of six months, “Catharine” (her true name is never disclosed), inherits his estate.

Seducing and marrying toy company owner Ben Dumers, she subsequently poisons a bottle of expensive liquor, which kills him while “Marielle” is on a trip away from home.

“Margaret” dazzles wealthy curator William McCrory, who has a convenient allergy to penicillin, resulting in a whirlwind romance and marriage.

A skeptical Paul informs Alexandra that “Renée,” who is independently wealthy, insisted they both amend their wills leaving their entire estates to a cancer charity.

Film4 notes that Black Widow succeeds through Rafelson's "menacing direction" and Debra Winger's "convincing struggle with temptation," while Theresa Russell "steals the show as the sexily assured devil sitting on her tracker's shoulder.

"[4] Vincent Canby of The New York Times writes that while the film promises more than it can deliver, its classy looks make it both soothing and "redeemingly funny, in part, at least, for not becoming mired in its own darker possibilities."

He praises Winger for "the gift of seeming always to have hidden reserves of feeling that might erupt in chaos at any minute," while Russell "comes into her own" in the film, and has "a clear-eyed sweetness that adds unexpected dimension to the homicidal Catharine.

"[5] Roger Ebert gave Black Widow a mixed rating of 2.5 out of 4 stars, praising the performances by the main actors yet lamenting that "The movie makes no effort to keep us in suspense," by revealing too much early on about Russell's character.