Babadook explained tells the story of Amelia is raising her son, Samuel alone. An unfortunate car accident killed her husband and Samuel’s father. He died while trying to rush Amelia to the hospital to deliver Samuel. She and Samuel live alone.
Samuel has the common childhood fear of monsters, thinking they are lurking under his bed and in the closet. Amelia tries to comfort him and repeatedly tells him he shouldn’t be afraid of things that don’t exist. She and Sam have a bedtime ritual of him choosing a book for her to read to him just before he sleeps. One night Sam selects a book entitled, ‘Mister Babadook.’
The book was so terrifying to Sam that he started crying and was inconsolable. Crying and screaming, he lay in Amelia’s lap, until she was forced to read a different book to calm him down. After he falls asleep, Amelia takes a closer look at the pages and discovers that the Babadook comes to a child in disguise, asking to be let in. He then asks the child’s mother the same thing. Finally, it drops its disguise and haunts both. Oddly, she looks again, and the final pages are empty. Shocked and horrified, Amelia tears the images of the Babadook from the book and throws them in the garbage.
Samuel starts behaving badly and blaming the Babadook for his mischief. Like any mother, she’s sure Samuel is just making things up, until she starts to feel some strange sensations. Then she hears a knock on the door. After she opens it, there’s no one there, but the knocking continues. She opens the door once more, but this time she finds the Babadook explained lying on the ground. When she examines the book, she discovers all the pages there. They have been glued back into their original places. The empty pages that were in the back of the book now have images of the Babadook following Amelia and killing Samuel. Amelia is so shocked; she burns the book.
After the shock of seeing those horrifying images of her and her son, she gets stressed and paranoid. Stranger things begin to happen and Amelia fears closing her eyes to sleep. After staying up two nights in a row, Amelia cannot offer motherly attention when Samuel needs it. Instead, she bursts into an angry outburst with a strange voice emanating from her. This anger is only aggravated when she overhears Samuel talking to their neighbor, Mrs. Roach who has Parkinsons.
She is angered by this, dismisses it, and focuses on taking her rage out on the dog by killing it. Still enraged, she chases Samuel. Amelia catches Samuel and, in an effort, to get away, Samuel throws a hard object hitting her in the head and knocking her out. Sam ties his mother up and stays with her until she awakes. After she is released, she later chokes Sam when he tries to hug her. It’s after a fight with her inner self and Sam gently stroking her cheek that she finally releases him. Amelia then starts choking and vomits up something black (Babadook). Sam tells her after seeing the expulsion, that she’s free. But he follows that statement with a declaration that they cannot make the Babadook go away. Suddenly, Sam is pulled away by an invisible force.
Amelia yells at the force, telling it, it is not welcomed in her home and is trespassing. Confronting Amelia, the force turns into a shadow and runs into the basement when she shows no fear. Everything seems to be back to normal as Amelia and Sam prepare to celebrate Sam’s birthday which coincided with his father’s death, so it was never celebrated. On his seventh birthday now, they were celebrating. Oddly, Amelia collects some maggots and worms and then heads for the basement. The end.