After a night out of partying and left behind by her friends, Ava wakes up and sneaks back home only to find that she's already safe in bed. But that's not Ava - it's someone who looks just like her. A time-traveling fugitive has stolen Ava's body, her identity, and her life. What's more -- she's not alone. There are others, hiding in the past, secretly living among us, plotting to alter the future. Without her body, Ava is a virtual ghost, silent and invisible to the world. And, so far as she knows, she's the only one who can stop them and put the timeline back on course. 第N种时空穿梭的方式。 夜晚派对之后，艾娃离开了她的朋友，偷偷溜回家里，第二天醒来，发现床上的自己安然无恙，但那不是艾娃，而是一个长得像她的人。一个来自未来的女人窃取了艾娃的身体，占据了艾娃的身份和生命。而且她并不孤单，因为还有其他人也躲藏在过去，偷偷地生活在我们中间，密谋改变未来。失去了身体，艾娃是一个虚拟的幽灵，不能说话，没有形体。据她所知，她是唯一能阻止他们的人，并重新夺回时间生命线。
