Jonathan Wells comes to live with his family after inheriting a house through his uncle’s will.
Jonathan, who had wanted to know more about his uncle, receives a note from his grandmother warning him not to go down into the basement of his uncle, Edmond Wells. However, due to a chance incident, Jonathan ends up entering the basement once and afterward, as if possessed, he keeps returning to it.
At the same time, in ant society, Scout Ant No. 327 is the first to awaken from hibernation in winter and is tasked with heading out with his comrades on a scouting mission. During that mission, all the scout ants except No. 327 are slaughtered without even knowing why.
Judging that danger is approaching the colony, No. 327 gathers like-minded companions to warn the colony of the threat. While being pursued by ants that emit a “rock-like scent” that puts his life in danger, he draws closer to the truth that the colony has been hiding.