After having her strongest puppet defeated by Tanjiro and Inosuke, the Mother Spider Demon has been decapitated by Tanjiro. She expresses the unexpected feeling of warmth and gentleness similar to a "spring rain" and her inability to feel any pain despite her dying.
The scene flashes back to an encounter that she had, the Mother Demon is on the floor withering in pain at the feet of another demon. She's bleeding from her eye and is apologizing for angering him, and pleads to know of what she did to upset him. Rui is seen hovering above the pair, and bluntly states that her offense was "not knowing why he's angry." 
Watching from behind a tree is another younger male demon, who reveals that the one attacking the Mother demon is known as the "Father" demon. In a nearby tree,there is a second female demon who watches the Father demon once again attack the Mother demon with a concerned look on her face, but she does not intervene.
As the flashback ends and the Mother demon experiences her final moments, she witnesses Tanjiro's "kind, practically transparent eyes" and is reminded of the person who used to love her when she was a human. Before disintegrating entirely, she warns Tanjiro that one of the Twelve Demon Moons is present in the forest and that he must beware.
Tanjiro remains shocked and questions her final words. He realizes that the Demon Moons contain high concentrations of Muzan Kibutsuji's blood, and that he would need to collect it in order to create a cure for Nezuko. Tanjiro snaps back to reality and returns to check on Inosuke, he informs him that he had defeated the Mother Spider Demon and asks if he is alright. Despite Inosuke's proclamation of his strength, Tanjiro notices the gory wounds and feels guilty for failing to protect Inosuke as well as the swordsmen who were killed.
He describes how the Mother Spider Demon smelled specifically of suffering and fear, giving the impression that she longed for death. The pile of unanswered questions as to what is occurring on the mountain continues to grow.
Elsewhere is the forest, Zenitsu is seen hurting his hand, and building up with rage as he treads up the mountain. He becomes more annoyed with a factor of things such as his inability to find Tanjiro and Inosuke, the unusual pungent odor, as well as the "gross" scattering sounds of the spiders. Zenitsu loses his patience and turns around to scold the arachnids responsible for the sound, but to his horror he discovers the body of a large spider with a human head staring back at him.
Zenitsu sprints away in fear questioning what he just witnessed, trying to convince himself that he is simply dreaming. He stops in his tracks and loudly begs to simply be woken up from his nightmare. As he looks up into the sky, he discovers a cabin being suspended by threads with humanoid spiders dangling below. Zenitsu is frozen with shock but is suddenly taken aback by the nose-burning odor. At that moment a creaking sound is heard coming the cabin, and a human sized spider demon descends from a thread.
Zenitsu is overcome with shock due to the size of the demon, and decides to flee rather then face the creature. However as he runs away, the demon claims that it is useless to run away. He advises Zenitsu to take a look at his hand, and when Zenitsu gazes down, he discovers his hand beginning to deform. The demon tells Zenitsu that the injury he sustained earlier was a spider bite that had injected him with poison.
The chapter concludes with the spider demon eerily claiming that within a few hours, Zenitsu will transform into a spider and become of his slaves.
Characters in Order of Appearance
- Mother Spider Demon
- Tanjiro Kamado
- Father Spider Demon
- Older Brother Spider Demon
- Older Sister Spider Demon
- Inosuke Hashibira
- Zenitsu Agatsuma