Perfect synchronization. Flawless harmonics. Absolute unity.
Seventeen-year-old Melody Chen returns to Resonance Falls High School after three months at the Braddock Auditory Processing Center, still struggling with lifelong amusia—an inability to process musical tones that teachers and doctors have always labeled a defect. But what awaits her isn't normal teenage life; it's a town transforming into something inhuman. Her classmates move with unsettling mathematical precision, heads nodding to invisible rhythms. Her best friend Isaac speaks in calculated patterns, his usual animation replaced by something mechanical and synchronized. And at the center of it all—ECHO, a viral music app that everyone is obsessed with, but which causes Melody nothing but painful static when she tries to listen. As the strange behaviors escalate—students arranged in concentric circles humming complex patterns that shatter glass, teachers conducting humming exercises between classes, classmates developing physical modifications like sound holes in their ribcages—Melody discovers a shocking truth: her mother's research wasn't meant to cure amusia, but to engineer immunity against an interdimensional entity that exists in mathematical spaces between sound frequencies. The entity doesn't just want to control humans; it wants to transform them into a living instrument for its manifestation. Resonance Falls itself—with its acoustically designed buildings, bell tower, and limestone caverns—was built as the perfect amplifier for "the convergence," when every transformed person will become part of the entity's body. As reality begins to thin around the bell tower and Melody's own father succumbs to the entity's control, she must use neural amplifiers designed specifically for her unique brain configuration to generate counterharmonics powerful enough to collapse the convergence—even if it means permanently destroying her adaptive structures and leaving herself completely deaf. In a race against the third and final bell toll, Melody discovers that what made her different wasn't a deficit to be fixed—it was humanity's last line of defense against perfect, beautiful enslavement.

Some voices refuse to sing in harmony. Some frequencies should never be allowed to resonate.