"妈妈是谋杀者"跟随卡琳娜,因为她意识到她的新最好的朋友发生了一些险恶的事情。卡琳娜幸福地结婚了,想在一个良好和安全的郊区社区建立一个家庭。当他们搬到一个新的地方,卡琳娜很高兴与莱娜和她的小女儿联系。When Karina becomes friends with Lena and her daughter Mallie, she begins to suspect that Mallie isn't Lena's daughter at all, but a girl named Emily who was kidnapped from her biological parents several years prior.