A witty, witchy fantasy murder mystery packed with ancient magic and fiendish puzzles. When Cornelia's twin sisters are taken by the Wickermere Reaper, Mallory, Diana and Theodore must race against time to uncover the buried secrets of the Broadwicks before it's too late.

The summer after the events of The Undead Complex, the unthinkable finally happens—Cornelia's money is running out. Estranged from her family, furious at her parents following recent revelations, the Broadwick heir finds herself living on her own resources for the first time.

Meanwhile two crimes are rocking the Apparent community. The Wrackton Digger is stealing bodies from the cemetery, and a new serial killer—the Wickermere Reaper—has emerged. But when the Reaper snatches their next victims—Cornelia's twin sisters—she must return to her family's home, and seat of the Ghoul Council, to conduct the search.

With their resources split, and a ticking clock on the race to save the twins, The Undetectables must do what they do best—solve the strangest, most well-hidden magical mysteries to save the people they love.