在这部血腥玛丽剧情/悬疑/惊悚/恐怖片中,在攜手踏入禮堂前夕，尚恩與艾美一同參加好友的婚禮，先行感受新人幸福的甜美氛圍。然而尚恩卻對初次見面的瑪莉產生迷戀，整夜心神不寧的他還為此與艾美起了爭執，而在回家途中撞上出現在路中央的瑪莉!!當尚恩在醫院醒來，發現艾美已陷入昏迷，但在接著詢問瑪莉的狀況時，眾人卻說從未見過這號人物....
Six months before his wedding, Shawn is suddenly filled with doubt. Maybe it was the family wedding, maybe it was his friends, maybe all it took was the beautiful girl in white. Before he knows it, casual glances turn into something more. His fiancé, Amy, knows things aren't right, but Shawn isn't talking, that is, until the girl in white hitches a ride. Now the glances and guilt become an argument, ending with the girl walking down the dark road again. The fight continues and when Amy gets suspicious, she forces Shawn to turn the car around to find the girl, but Shawn doesn't see her until she darts in front of the car. The accident leaves Amy in a coma, and Shawn bruised, with few answers and unable to separate the girl in white from facts and legend. When he returns to the ballroom, Wilkes, the owner, lets Shawn in on the decades old secret: Mary is in a dance with the devil. Now sins, sanity and Amy's salvation are at stake as Shawn searches for a way to bring her back, and Mary ...
