In a stark desert confrontation that opens the story, three Arab smugglers pursue a nest of spiders, using poison gas to flush them out. The pursuit ends violently when one of the smugglers is bitten and writhes in pain as more spiders erupt from the nest. The others grapple with the danger, netting some of the arachnids in plastic containers, until the bitten man is killed by his companion with a machete. The trio’s desperate escape follows, their truck carrying them away from the immediate threat and the tense moment of isolation that comes with it.
A single spider survives the chaos and makes a perilous journey far from its origin. It is transported to a convenience store in Paris, and there a sneakers dealer and exotic animal lover named Kaleb buys the spider along with a pair of earrings. This small purchase kicks off a chain of everyday life colliding with a creeping horror as Kaleb tries to live in a bustling, multicultural suburb. At home, Kaleb’s world is a jumble of ordinary concerns: he seizes a troublemaker’s bag filled with fireworks meant for a prank, his bicycle-thieving friend Mathys reminds him that he still owes Toumani for sneakers, and he argues with his sister Manon about whether they should sell their deceased mother’s house.
Kaleb’s life becomes entangled in the spider’s shadow when he keeps the spider in his room, only to lose it later after he gifts the earrings to his neighbor, Claudia, at her farewell party. The loss unsettles him, and in a moment of restlessness he swipes Toumani’s sneakers and ends up sleeping in the living room, trying to keep the creature hidden from view even as the danger grows.
The next day, Kaleb clashes with his former friend Jordy as he helps Lila, Manon, and Mathys renovate the house. Kaleb’s world collides with a tense, suspicious atmosphere when he sells sneakers to Toumani, drawing the ire of a xenophobic resident Gilles who suspects drug dealing. The moment of danger intensifies when Toumani is bitten by spiders crawling out of a sneaker, and a heated exchange with Kaleb ends abruptly when Toumani is found dead in his apartment. The authorities wheel Toumani’s body away and seal the building, plunging the neighborhood into fear and a stifling lockdown.
Gilles remains convinced that Toumani’s death is drug-related, a charge Kaleb vigorously denies. In the ensuing chaos, Jordy helps Lila in a bathroom scare as a spider and its offspring burst forth, prompting the group to realize that the spiders are multiplying with alarming speed. Kaleb is forced to confront the truth: he inadvertently caused the infestation, his actions reflected in the shoebox containing the cocoon from the spider that escaped. Jordy, Manon, and Lila are horrified as the infestation spreads, trapping residents and turning the suburb into a battlefield between people and a rapid-reproducing threat.
With the danger escalating, the group discovers a fragile escape plan. Gilles launches an attack, stabbing open a sealed shoebox he suspects holds narcotics, only to be overwhelmed by the spiders inside. They navigate a treacherous infested hallway, using a time-sensitive hallway light to pause the onslaught of the creatures, but the safety of the path dissolves when police gas and gunfire force them back into the darkness. Jordy is ensnared in a web and urges the others to leave him behind. Mathys reveals that he has been bitten, and he sacrifices himself by rushing through the oppressive corridor, igniting a fight between the spiders and the armed officers.
Kaleb, unsteady but determined, frees Lila and urges her to stay in the car while he searches for Manon. The siblings reunite, though Kaleb is shot in the leg during the struggle. They find refuge in a van, where Manon applies pressure to the wound as they patch up their differences. In a tense climax, the danger closes in as spiders close the distance. Lila’s car headlights become a sudden beacon that clears a path, and Kaleb leads Manon toward safety, aided by a large spider that blocks their pursuers momentarily and then, at last, Kaleb opens the garage door to escape.
The aftermath settles on a bleak note as Manon and Lila watch the suburb crumble, a visual of a community under siege. Kaleb digs a shoebox containing a childhood photo of himself with a friend in the woods, a small relic of a gentler past, and places it in the ground. He allows a spider that crawls onto his shoulder to rest in the palm of his hand before finally blowing it away, a quiet, symbolic act of release as the city’s catastrophe recedes into memory.
