本片是著名商业片导演彼得叶茨执导的好莱坞新派警匪片的先锋之作。本片描述一名忠心的旧金山警探奉命保护一名将出庭作证的黑手党分子。证人所提供的证据大大有助于摧毁黑手党的重要组织，但此人却被暗杀。警探感到事态可疑，于是拼全力追查凶手的底细。

After secret agent Michael Scarn (played by Scott) is forced into retirement due to the death of his wife Catherine Zeta-Scarn, the President of the United States of America (played by Darryl Philbin) requests that he prevent Goldenface (played by Jim Halpert) from blowing up the NHL All-Star Game and killing several hostages. Scarn goes undercover and learns how to play hockey, killing another hockey player (played by Oscar Martinez) to make it into the game, but after confronting Goldenface, he is shot. He later recuperates but learns that the President was in on it all along. Depressed, he goes to a bar to drown his sorrows. The patrons of the bar sing a song called "The Scarn" which he danced to with his wife, which cheers Scarn up immensely. With his courage restored, Scarn is able to save the day and blow up Goldenface in the process.

香港天王巨星刘伟驰（刘德华 饰）从影四十年，一直渴望得影帝。他决定与导演林浩（宁浩 饰）合作拍摄农村题材影片，从而在电影节赢得国际声誉。为此，刘伟驰深入农村体验生活、亲自拉投资、拒绝用替身，却因此引发了一系列令人哭笑不得的荒诞闹剧，也展现了娱乐圈的众生百态。

影片根据相思树真实故事改编创作。1984年初夏，时任连长李相恩带队巡逻途中在哈拉哈河突遇险情，李相恩为救战友英勇牺牲。妻子郭凤荣为寄托哀思，在哨所旁种下一棵樟子松。2010年妻子郭凤荣因病去世前，特意嘱托儿子李心要把自己的骨灰撒在哈拉哈河，继续陪伴丈夫守好祖国北疆。