A couple on the verge of a nasty divorce attempt to sell their empty love nest and move on with their lives, separately. After a successful open house they are horrified to discover, days later, that a potential buyer didn't leave their home. While Alice is being held captive in the basement, the unannounced house guest moves in upstairs. She senses her capture is being kept a rebellious secret. She knows her way only way out if she can only get out alive.

一对濒临离婚的夫妇试图卖掉他们空荡荡的爱巢，然后各自开始新生活。在一次成功的开放参观日之后，他们惊恐地发现，几天后，一个潜在的买家并没有离开他们的家。当爱丽丝被关在地下室时，一位不速之客搬到了楼上。她感觉到她的被囚禁被关押了一段时间……