1929年的好莱坞,一位西部片演员汤姆米克斯(布鲁斯威利饰)正要在一部默片里饰演美国西部传奇人物-执法悍将卫特厄普(詹姆斯嘉纳饰),但却赫然发现卫特厄普竟然就是该片的技术顾问,不久两人就便成了好朋友。此时片厂里却发生了一桩命案,于是这个由前西部警长加上西部片演员的全新组合便决定携手合作办案,好找出杀人凶手。Whilst making a silent film about the life of the legendary lawman Wyatt Earp, veteran actor 'Tom Mix' (Bruce Willis) discovers that the real Earp ('James Garner') is on the film set as a technical advisor. The two become friends, but when a murder takes place, the two become partners and set about tracking down the killer.