你是否曾幻想过可以在多重身份之间切换自如，可以随时开始新的生活？事实上，艾莉丝这么做已经15年了。然而就在一次聚会中，她曾经作为“珍妮”时的前男友汤姆却认出了她。汤姆坚信他们之间颇有渊源，但艾莉丝只是匆忙离开，拒绝相认。汤姆想要知道十年前究竟发生了什么，艾莉丝究竟为何会有如此丰富的经历。在汤姆的坚持之下，两人终于敞开心扉彻夜长谈…… 《完全陌生》描绘了两种人的生活轨迹，通过大量感官特写来探讨人格的多面性。

  Complete Unknown is Marston's first English language film and centers on Tom (Shannon) and a mysterious woman named Alice (Weisz). When Tom and his wife host a dinner party to celebrate his birthday, one of their guests brings a date named Alice. Tom is convinced he knows her even though she's going by a different name with a different biography, and she's not acknowledging she knows him. We soon find ourselves on an all-night odyssey with two characters, one needing to make a change in his life, the other questioning how to stop changing.