The Mind Flayer (The Shadow Monster): The shadow that turns its victims into its executioners

In the third episode of the second season of Stranger Things (“The Pollywog”), Will Byers has another of his episodes at school. A wave of shadow chases him down the hallway and he runs out onto the playing field. There he remembers the advice of Bob, his mother’s boyfriend: stand up to what scares you. He turns around and shouts at the shadow to go away. It does not. One of its smoky tendrils wraps around him and pours into his eyes, nose and mouth. That shadow is the Mind Flayer: a gigantic, spider-shaped entity that lives in the Upside Down, the show’s parallel dimension, and controls all of its creatures, from the Demogorgons to the vines, as a single mind. It is the main villain of the second and third seasons. Its victims do not die right away: they obey. (Warning: this case file reveals the end of the series, including what the fourth and fifth seasons tell us about the Mind Flayer and Vecna.)

// The theoryThe force that teaches you to use force

In Crime and Coercion (2000), the sociologist Mark Colvin, who had studied the 1980 riot at the Penitentiary of New Mexico, set out the theory of differential coercion. Coercion is any force that makes someone act out of the fear or anxiety it causes, and it has two faces: the interpersonal (punishment, threats, withdrawn affection) and the impersonal (poverty, unemployment, a world at war around you). It leaves four marks: more anger, less self-control, weaker bonds and what Colvin calls coercive ideation, the conviction that whatever squeezes you can only be beaten by squeezing harder. Degree matters, but so does consistency: erratic coercion, which comes when you least expect it and without your knowing why, is what produces the chronic offender. In 2002, with Francis Cullen and Thomas Vander Ven, Colvin added the counterweight: social support protects against what coercion pushes.

// The subjectThe storm that comes in through the mouth

In the first episode of the second season (“MADMAX”), Will opens the front door at night and sees the Upside Down: a storm of red lightning and, in the sky, a huge silhouette with spider legs. After the possession his temperature drops, and he tells his mother that he likes it cold (episode 4, “Will the Wise”). In the sixth (“The Spy”), Will points on the map of the tunnels to an open space that, he says, the monster does not want him to see. The lab’s soldiers go in, and a pack of young Demogorgons kills them. Will apologizes: he made him do it, because the soldiers had upset him by burning the tunnels. In the ninth (“The Gate”) his mother, his brother and Nancy tie him to a bed surrounded by heaters to drive it out with heat. Will breaks free and strangles his mother, Joyce, until Nancy burns him with a fire poker. The shadow leaves his body as black smoke, and Eleven closes the gate between the two worlds.

A fragment stayed hidden in an abandoned steel works, and in the summer of 1985 a gate opened by the Soviets wakes it up. In the first episode of the third season, a tendril drags Billy Hargrove into the steel works’ basement; in the second, Billy delivers Heather, a fellow lifeguard, to the monster. In the fourth (“The Sauna Test”), the kids lock Billy in the sauna. He weeps, apologizes to Max and tells her that a “giant shadow” made him do it; a moment later he tries to stab her with a shard of tile. In the sixth, Eleven enters his memories and sees his father, Neil, humiliating him as a boy and abusing his mother, who ends up leaving. In the eighth, Eleven tells him the memory of his mother on the beach, and Billy puts himself between the monster and her, and dies. In the fourth season finale, Vecna reveals to Eleven that he found that mass of particles in another dimension and gave it its shape. The fifth (2025) adds the final twist: as a boy, in a cave, Henry Creel touched a stone holding those particles, and a voice asked him to come and find it. In the finale (“The Rightside Up”), the heroes kill the monster’s body and Joyce finishes off Vecna.

// The crackThe possessed do not choose

The metaphor works, but it has a catch. In Colvin, coercion acts through the person: it changes what they feel and think, and then they are the ones who decide. The Mind Flayer, by contrast, replaces the will. A possessed person has neither anger nor coercive ideation: they have a master. The series itself wavers. In the sauna, Billy says the shadow made him do it, and in that same moment he tries to stab his stepsister. And in the series finale, when Will tries to convince him that the Mind Flayer has been using him, Henry rejects the role of victim: the creature showed him that the world is broken, and neither of them controlled the other, because they were one. The writers, according to Netflix’s official site, leave open whether the boy in the cave chose or was controlled from the start. That doubt is exactly criminology’s territory: coercion explains, but it does not decide for anyone.

The second lesson lies in how the control breaks. Will is not saved by the heaters alone. In the eighth episode, tied to a chair, he listens to his mother, his brother and Mike tell him memories they share with him, and meanwhile he taps out in Morse code, with one finger, the instruction for beating the monster: close the gate. Billy is freed by the memory of his mother. This is Colvin, Cullen and Vander Ven’s counterweight: social support against coercion. And the levels should not be confused. Billy’s childhood explains why the shadow found fertile ground, but his violence in the second season against Max, Lucas and Steve comes before the possession and is his own. Explaining is not excusing, not even when the force that pushes comes from another dimension.