Claire, an English teacher, hears a mysterious rumbling sound causing migraines and visions. Despite being undetectable to others, her student Kyle also hears it. Together they investigate the source of this unsettling phenomenon.

Claire and Kyle join a group embracing a mysterious hum, but Kyle's mother discovers their secret meetings, leading to potential conflict.

A woman's grip on reality slips as an otherworldly sound consumes her life. A tragic ending befalls her support group's final meetup.