Net nichego silnee materinskoy lyubvi, no inogda ona imeet razrushitelnuyu silu, potomu chto, kak i lyuboe lekarstvo, v slishkom bolshih dozah ona stanovitsya yadom.
Felisite Kaznav - voploschenie chrezmernoy zaboty, ona otnositsya k svoemu pyatidesyatiletnemu synu kak k slabomu i glupomu rebenku. Odnako vopreki vole materi on zhenitsya na molodoy sosedke Matilde. Felisite sgoraet ot revnosti i klyanetsya nikogda ne otpuskat syna, poetomu nachinaet nastoyaschuyu voynu so svoim istinnym vragom - raschetlivoy nevestkoy.