数年前,艾米莉亚·范宁(艾斯·戴维斯 Essie Davis 饰)和丈夫遭遇一场严重车祸,丈夫不幸在这场意外中身亡。在此之后,艾米莉亚一面在养老院辛勤工作,一面又要照顾年幼的儿子塞缪尔(诺亚·维斯曼 Noah Wiseman 饰)。没有父亲的保护,塞缪尔从小害怕鬼怪,与之相对又表现出极其暴力叛逆的言行举止。带着危险品上学的塞缪尔遭到校方的斥责,艾米莉亚无奈暂时将其托付给克莱尔阿姨照看。 某晚,塞缪尔选了一本从未见过的绘本《巴巴杜先生》作睡前故事,因故事太过诡异恐怖,艾米莉亚中止了阅读,谁知小塞缪尔却仿佛着魔了一般。他声称巴巴杜来到了家里,小家伙的举止越来越离经叛道,而各种可怕的现象也接二连三出现……Amelia, who lost her husband in a car crash on the way to give birth to Samuel, their only child, struggles to cope with her fate as a single mom. Samuel's constant fear of monsters and violent reaction to overcome the fear doesn't help her cause either, which makes her friends become distant. When things can not get any worse, they read a strange book in their house about the 'Babadook' monster that hides in the dark areas of their house. Even Amelia seems to feel the effect of Babadook and desperately tries in vain to destroy the book. The nightmarish experiences the two encounter form the rest of the story.