What if you came home one day to find some weirdo living in your house? What if that weirdo, in a barely understandable language, explained that he was your son? But you knew for a fact you had no children. This is what happened to André and Laurence Prioux, a bourgeois couple, stylishly living in a quiet upscale suburb.
　　Convinced they are victims of an error or a con man, André wants nothing to do with Patrick. But Laurence, faced with the inexplicable, suddenly becomes the mother she never was and welcomes with open arms this long-lost son, who sprung out of nowhere with his pregnant fiancée. And her dog. When a childless couple encounters family... Or makes it up.

　　人类和众多外星种族共同生活在一个名为千星之城阿尔法的繁华星际大都市，数百年来，千星之城阿尔法成为各族群和平共处的美妙天堂，它繁荣昌盛。韦勒瑞恩（戴恩·德哈恩 Dane DeHaan 饰）和洛瑞琳（卡拉·迪瓦伊 Cara Delevingne 饰）被选择成为阿尔法的守护者，他们俩是警卫部的执行人员，被任命去拦截一种稀有物品的交易。这种稀有物品与一个本该在数十年前就消失的稀有族群存在神秘的关联。然后他们来到了巨大的千星之城阿尔法城，这时他们的指挥官Arun Filitt（克里夫·欧文饰）在指挥中心遭到绑架，这对搭档开始意识到手中物品的不寻常价值。二人追寻凶手，发现自己身陷一场正在发酵的星际事件中……