This October 31st, All Hallow's Eve is changed forever for one sleepy little town when three youngsters team up to overthrow an alien invasion by sending those witches back from whence they came. "Trick or treat, smell my feet, witches came for people meat"...。六年前女生宿舍的恶作剧事件,使得女大学生王玥彤失足坠楼而亡。恶作剧的主谋非但没有后悔,反而要消灭更多的证据。六年后,这起“坠楼事故”再次被提起时,更多的人陷进了这起迷雾一样的案件中……。