今天是出轨的好日子

　　George is the scapegoat of his classmates. One day he cracks and shoots them. His best and only friend Blaise is accused in his place and sentenced to 7 years in a psychiatric hospital. At the day of his release, Blaise realizes he only has one family: his best friend George. But he does not want to hear about his childhood friend, as he tries to integrate with the "Chivers" a gang whose members wear red jackets and boots, drink milk, drive sport trucks and play an incomprehensible and violent game that mixes cricket and mental arithmetic.

　　30年代的香港，社局动荡，黑帮林立。香港大亨胡老头这日找到私家侦探哎吆（林子祥 饰），要求其调查胡太太，因为他觉得胡太太这些天表现奇怪。哎吆调查后发现，原来是坏蛋神父卡邦派（麦嘉 饰）人勾搭上了胡太，意欲偷取胡老头价值连城的股票。他们这一计划遭哎吆撞破后，四处追杀哎吆。　　哎吆亡命之际，又发现了胡老头其实并非什么香港大亨，只是一名老千，他来香港的目的就是要骗卡邦等流氓的钱。胡老头邀请哎吆入伙，一起设局骗卡邦。和好友探长罗宾（泰迪•罗宾 饰）商量后，哎吆决定来个将计就计。

　　影片改编自真实故事，讲述两名时运不佳的音乐人（休·杰克曼与凯特·哈德森 饰）组成一支充满欢乐气氛的尼尔·戴门致敬乐团，证明了寻找爱情和追逐梦想永远不会太晚。