The Limestone Choir

Beneath the limestone bedrock of Briar Hollow, Texas, something has been listening.

When strange chanting begins under the Museum of the Unseen, Rowan and Maeve assume it's acoustics-until recordings start changing on their own. Words appear where none were spoken. Voices multiply. The sound doesn't echo. It rehearses.

As townspeople begin sleepwalking toward the museum, drawn by a harmony they cannot hear, Rowan discovers the truth: the building is not a museum. It is an engine. The artifact...