When Allan becomes a quadriplegic he loses all hope for living until he meets Ella - a monkey trained to fetch and carry for him around the house, obeying him in all things. But Ella is part of another experiment, and when she starts responding to Allan's underlying rage and frustration she has the ability to carry out her master's darkest wishes. 人之欲，兽之情。 Allan自一场意外事故后沦为自暴自弃的神经机能发生障碍者，友人致力于动物智力开发研究，并将一研究对象Ella，一只聪明的猴子赠予Allan，聪明的Ella肩负起起Allan的生活起居。但好景不长，猴子Ella开始显露出强烈的控制欲和疯狂的报复心，甚至伤害了Allan至亲的人。最后，Allan又能否走出这一困境呢?
