小女孩Aurora(Sloan)去尋求鄰居(米科爾森)的幫助：她相信家人被住在自己床底下的一個妖怪吃掉了，而這個鄰居恰巧是訓練有素的殺手，并且確信Aurora的父母是被一群來殺自己的人給誤殺，于是，殺手的第一要務變成了保護小女孩的安全，兩人一起上路，并肩面對自身的惡魔。

　　3年前，話劇老師林曉陽（林嘉欣飾）的弟弟被綁架，案件交由高級督察何宛真（劉若英飾）及智叔（張兆輝飾）負責，可是在追捕的過程中，疑犯因爭吵墜樓身亡，林曉陽就此埋下了怨恨。　　三年后，林曉陽患病的丈夫（趙會南飾）病情加重，需要一千萬才能有治好的希望，林曉陽動了綁架富豪王森（郭 濤飾）兒子的念頭。多日來林曉陽跟她從尼泊爾認識的同伙跟蹤小孩動向，后來決定在一個傍晚下手。剛好案子也是有何宛真接手，就讓林曉陽有了報復的心理，何宛真為了救回孩子只好服從，可她萬萬沒有想到，原來王森的兒子，跟自己的兒子調換了衣服穿，被林曉陽綁架的正是何宛真的兒子。　　兩個女人，都為著心愛的親人在綁架案中斗志斗勇，展開激烈的較量。

　　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...

簡和伴侶的森林之旅出了岔子，當一個陌生人出現并質疑他們關系的真實性時，她開始懷疑自己是否真正掌握了現實的全部真相。