Using re-enactments and first person interviews, EVIL IN-LAW reveals relationships that were nearly ruined when maniacal mothers-in-law meddled in marriages. Each 60-minute episode chronicles one or two stories, including: the mother who slowly poisoned her daughter-in-law so she could raise the grandchildren as her own; the mother who tried to seduce her son-in-law because she was jealous of her own daughter; the mother who faked a fatal illness to get her son to turn on his wife and move back in with mommy; the mother who nearly killed her grandson, setting off a chain of deadly events when her daughter-in-law left her son; the mother who raised her grandson like her own when her son lost interest in family matters, while treating her daughter-in-law like a housekeeper; and many more tales of marriages ruined by mothers-in-law, often with deadly consequences.