在这部我妹妹的连环杀手男友惊悚/恐怖/犯罪片中,麦迪是一名当地记者，正在调查一系列针对长相相似的女性的杀戮事件，当她的妹妹奥利维亚在自己家中遭到袭击时，她猝不及防。为了谨慎起见，麦迪建议他们参加一个自卫课程。当奥利维亚开始爱上他们的教练时，麦迪开始怀疑，因为他拒绝透露任何关于自己的事情，并试图在关系变成致命的痴迷之前进行干预。
Maddie, a local reporter investigating a series of killings targeting similar looking women is caught off guard when her younger sister Olivia, is attacked in her own home. Urging on the side of caution, Maddie suggests they take a self-defense course. When Olivia starts to fall for their instructor, Maddie becomes skeptical when he refuses to reveal anything about himself, and tries to intervene before the relationship turns into a deadly obsession.
