In a time now lost in the mists of memory, the great King Arthur rules in the legendary citadel that is Camelot. His Knights of the Round Table perform acts of derring-do and spend their spare time jousting, much to the delight of the local citizens and especially to Princess Ilene, a guest at Camelot. Watching her from afar is a young, inexperienced squire called Valiant, and when the young Welsh princess is sent home to marry Prince Arn, Valiant contrives to accompany her masquerading as Sir Gawain. Meanwhile, the evil sorceress Morgan le Fey, sister to King Arthur, has convinced the tyrannical Sligon, ruler of the Viking kingdom of Thule, that he should steal Arthur's sword, the powerful and magical Excalibur, knowing that its loss could bring about Arthur's downfall. So into the fray comes Sligon's unstable and psychotic brother Thagnar, who manages to steal the sword. Pandemonium reigns. But Valiant is having problems of his own - kidnappers attempt to steal away the Princess, and after various skirmishes, including one with a mysterious character who lives in a cave and purloins treasure, women and other things of value, Valiant manages to return the Princess to her homeland - although he also manages to have a duel with the Princess' jealous fiancé, Prince Arn. All things converge as Valiant is finally informed of his heritage by the stranger from the cave... Boltar of Thule. He informs the lad that he is Prince Valiant, rightful heir to the kingdom of Thule, and with his help, Valiant returns to the land of his birth to rightfully claim what is his.

艾索（艾迪?墨菲 Eddie Murphy 饰）是底特律黑白两道的大名人，身为警探，却也不时干些偷鸡摸狗的勾当，而且他侦办案件时经常不按程序办事，上司对他十分头痛。这天，艾索因为敲诈烟贩而差点被开除出去，幸亏好运气才免遭于难。 　　艾索偶遇了一位刚出狱的好友，这人带着巨额的德国债券来到了底特律。两人重逢后不久，艾索的这位朋友就被谋杀了。深谙此事不简单，艾索开始了调查。他独自一人追踪嫌疑人维克多来到了好莱坞的比佛利山，正当他准备上前盘问时，却被当地警察带回了警局。当艾索调查得悉维多克的确在贩毒时，当地的警长同意介入调查，却将艾索打发回老家。艾索只好劝说当地的一名警员比利（祖德?莱茵霍尔德 Judge Reinhold 饰）和他合作，两人开始了私自调查。