因为找到一份新工作，西蒙·卡勒姆（杰森·贝特曼 Jason Bateman 饰）带着从事绘画设计工作的妻子萝宾（丽贝卡·豪尔 Rebecca Hall 饰）来到加州居住。西蒙的事业小有成就，夫妻俩和谐融洽，生活无忧无虑。在购物时，西蒙偶然重逢高中同学戈多（乔尔·埃哲顿 Joel Edgerton 饰），两人简单交谈后挥手告别。未过几天，戈多不请自来为夫妻带来了小礼物，当晚三个人共进晚餐，不过西蒙感觉并不十分愉快，显然他不太喜欢这个始终那么古怪的同学，相反萝宾倒有些欣赏这个热心的男子。在一次小的波折过后，西蒙终于决定张口要和完全不属于同一个世界的戈多绝交。 　　戈多面带失落，同时一种异样的表情在他脸上浮现……Simon and Robyn are a young married couple whose life is going just as planned until a chance encounter with an acquaintance from Simon's high school sends their world into a harrowing tailspin. Simon doesn't recognize Gordo at first, but after a series of uninvited encounters and mysterious gifts prove troubling, a horrifying secret from the past is uncovered after more than 20 years. As Robyn learns the unsettling truth about what happened between Simon and Gordo, she starts to question: how well do we really know the people closest to us, and are past bygones ever really bygones?