I watched an exceptionally good horror film on Netflix, called The Babadook. One thing I like to do after seeing a good movie is try to reverse engineer the screenplay. What was the spark that inspired the screenwriter?

In this case the spark was likely a familiar domestic scenario in fiction: what tvtropes.org calls “Maternal Death, Blame the Child” — i.e., the mother dies in childbirth, and the father resents the child.

In this breakout Australian film, the genders are reversed. It’s the father who dies in a horrific auto accident while rushing his pregnant wife to the hospital. Fast-forward seven years, and you have single mother Amelia, struggling to raise her stormy, high-strung son, Sam. The lines on Amelia’s face hint at the toll Sam has taken on her with his eccentric hyperactivity. At just seven years old, Sam has developed a spastic repertoire of magician’s tricks, while fashioning homespun mechanical weapons that shatter windows and break dishes.

The film makes clear Sam’s motive in demanding all of his mother’s attention. He’s afraid she doesn’t love him. It’s his greatest fear. And in a horror film, your greatest fear can turn murderous.

Amelia begins to fear this about herself, as well. Has she stopped loving her son? Though her affection for Sam is obvious, her sanity is wearing thin. She puts out Sam’s fires left and right: Sam ejected from school for bad behavior, Sam shoving his cousin out of her tree fort and breaking her nose.

Amelia is also horribly sleep deprived. With Sam’s birthday–also the anniversary of her husband’s death–fast approaching, she’s plagued by nightmares of the car crash that decapitated her husband seven years before.

Sam has nightmares, too. Amelia must soothe him long into the night. The best way is to let him sleep in her bed. But she’s robbed of her own sleep, as he clings to her. In two memorable close-ups, Sam’s hand grips her throat or he grinds his teeth right next to her ear.

As the sleep deprivation wears on her, Amelia begins to lose her temper. She snaps at Sam, curses, even. “If you’re so hungry, why don’t you eat shit!” She apologizes, horrified at herself.

But we’re not surprised. We see she’s on the verge of a nervous breakdown.

He slows her attack long enough to wrest her attention: “I know you don’t love me,” he shouts. “The Babadook won’t let you!”

It’s at that moment the film so movingly reveals the central metaphor: that Amelia’s grief at the loss of her husband poisons her relationship to her child. The Babadook represents her resentment. Resentment kills relationships.

At the risk of revealing too much, let’s just say Sam battles the Babadook to the end.