Twelve-year-old African American Opal investigates the disturbances in her apartment building that are interfering with the vital renovations.

Opal Watson is a young detective who loves solving mysteries, from lost pets to missing objects. After returning to Chicago from New Orleans, she's nervous about starting school and dealing with her Retinitis Pigmentosa, a degenerative eye disease. Opal is paired with a new student, Ivy, for a history project, but she's more focused on her friends, cousin Frank and best friend Madison. When Madison hears strange noises in their apartment building, the Crescent, and renovations disrupt the neighbors, Opal begins to investigate. The building is also threatened by developers who want to tear it down. As Opal delves deeper into the mystery, she faces her toughest case yet, wondering if she can solve it and uncover hidden truths along the way.