There isn't much crime in Stoneleigh, Massachusetts, a college town, a mountain getaway for the quietly rich. So when Edward Inman, owner of Stoneleigh Sentinel security, gets a late-night alarm from the home of one of his wealthiest clients, Doyle Cutler, he does a routine check and thinks nothing more of it—until a local student claims that she was sexually assaulted that night at Cutler’s house.　　Edward soon finds himself drawn into the girl's story, and his investigation leads him to his old girlfriend, whose teenage son may know the truth about what happened that night. Security is a timely, wry, and riveting story of adults and children, secret lives and civic culture, suspicion and sexual hysteria.

一群互不相识的陌生人与一个神秘的人物接触，他们相信这个人拥有给予任何愿望的力量，作为回报，他们必须执行他分配给他们的任务...

主人公罗伯特（马尔科·达莫雷 Marco D'Amore 饰）经营着一家专门提供别墅主人视频监控系统服务的公司。一个寒冷的冬夜，女孩玛利亚（玛雅·珊萨 Maya Sansa 饰）在街上遭遇了袭击，向多个别墅主人求救，但却得不到任何帮助。次日，罗伯特发现遭袭女孩正是他之前的员工沃尔特的女儿。　　事情变得更加复杂，因为沃尔特本人有酗酒问题，并被指控伤害玛利亚。然而，当女孩苏醒后，她却讲述了一个完全不同的故事。现在的问题是：到底是谁是真正的施暴者？警方怀疑沃尔特是凶手，甚至玛利亚学校的视频作业似乎证明了这一点。然而，还有第二个嫌疑人，名叫达里奥，监控录像显示，案发当晚，达里奥与玛利亚之间似乎存在某种关系。