交换：朋友的妻子2

　　全球突然出现了很多来自宇宙巨大的“入口”，世界一片混乱、陷入危机。这些扭曲现实的入口为何出现，它们的另一端是？

　　The nightmare was about a demonic possession. A long time ago, there was an evil in a small town and it was jealous of the girl and would never let her go, since the devil loved the girl. One night, the evil raped the girl and she became pregnant. After months the girl could not hide her baby, her father figured her secret out and clapped the girl in irons and locked her room door. But the evil put the gun to her father' temple and saved the girl. The father had a stroke and had been sleeping on the bed for three months and died. Time went on and the girl brought a child into the world. Naturally, people who were living in the village heard the story and they did not want to see neither the girl nor the baby since when the baby was born, plants dried in the field, fishes lost in the lake and people had prayed to the god for rain, but nothing changed in the village. People got so angry, dug a hole in front of the fountain, put her into the hole and threw stones at her face. The girl died soon after. The evil went off the deep end, took a revenge of the village and killed everyone except two sisters because the evil wanted them to take care of its baby...

 一个从事打扫工作的女子为纽约一座摩天大楼中的富人家工作，却被告知这里有一个供奉撒旦的邪教，每个月要杀一个人作为祭品，“今晚，选中了你……”

 由于两年前揭发同僚贪污，台北警官黄火土（梁家辉）被上级报复调入冷门的外事组工作，利益也曾连带受损的新同事对他怒言相向，加上妻子清芳（刘若英）受不了他长期不回家要求离婚，黄火土感觉他的世界正在逐渐四分五裂。就在此时，三宗受害者的身份并无关联的震惊了台湾社会的离奇命案发生，法医（杨贵媚）验尸发现他们都是因中一种神秘的黑霉菌产生幻觉而死，因为缺乏此方面的人才，当局从美国请来此种案例的侦办专家凯文莱特（David Morse）协助破案，黄火土重被任用。随着一桩令所有人都目瞪口呆的事实的被发现，一场围绕政治利益与民众利益的斗争也在黄火土和办案伙伴李丰博（戴立忍）及整个警察队伍之间展开。