菲尔（Bill Murray饰）是个气象播报员，每天除了在摄像机前给观众做风趣幽默的天气预报外，每年的2月2日他还要前往一个名为普苏塔尼的边境小镇，报导当地的土拨鼠日庆典。事实上，菲尔对这一节日相当嗤之以鼻并开始对工作感到厌倦，当他例行公事完成今年的报导后，便急不可待地想重返家园，却因为一场突如其来的暴风雪耽搁了。第2天醒来后，菲尔意外地发现时间仍然停留在前一天土拨鼠日，昨日的一切重新上演。惊讶、不信、刺激、狂喜、烦闷、焦虑、不安、绝望、倦怠等各种情绪轮流侵占菲尔的感官领域，可无论他如何选择度过这一天，他都始终无法再前进一步，开始了他重复的人生。

Once upon a time, the birds and the beasts fought each other in a war. It was a terrible conflict, and the clever bats would side with the birds when the birds were looking victorious, and then they would become allies of the beasts when that side was winning battles. At last the war came to an end, the two parties reached an amicable settlement, and a great party of friendship was held. But when it came to the turn of the bats to perform in the program, their fence-straddling tactics were exposed, and everyone refused to associate with them. Since that time, the bats have been too ashamed to show their faces during the day, coming out only at night to flit silently around.

香港皇家警察蒜头（吴奇隆 饰）与绰头（金城武 饰）是一对儿搭档，二人联袂破获毒品大案，上电视大出风头，原本就倍受女性欢迎的富二代蒜头更加惹眼，绰头却只有埋怨，并继续凭借三年前帮蒜头挡子弹的往事要其继续为自己埋单。失去了毒品的幕后毒枭视二人为眼中钉，施计陷害绰头拍下艳照，为此大为头疼的上司要求他们暂避风头，改换身份接下卧底任务。二人由此前往黄飞鸿中学，以便暗中保护来香港学习的大陆国防部长之女江美丽（杨采妮 饰）。黄飞鸿中学校如其名，教导主任乃是功夫高手，蒜头绰头兄弟俩因糟糕的成绩吃了不少皮肉之苦，警方担心二人因成绩差被退学，派出女警官叶老师（叶全真 饰）暗中相助。江美丽如期到校，为了尽到保护义务，众人令绰头出手追求江美丽……

一名年轻的维京王子，为了遭到谋杀的父亲，踏上一场冒险的复仇之路。