美国惊悚片。备受梦游症与噩梦困扰的研究生莎拉·福斯特，前往学校附属的睡眠研究中心求助。然而，在先进仪器监测下度过一夜以后，她发现现实世界与梦境微妙地交缠、变得难以分辨。

When wealthy couple Richard and Angela visit Marion and Alex in their decaying family home, their differing social and moral attitudes create uneasy tensions. An inharmonious evening of drunkenness and sexual rivalry soon turns bloody as the guests fall victim to an unhinged attacker.