The narrative begins in a hospital during a rest cure, where Letitia Carberry—better known as Tish—alongside her devoted friends Aggie and Lizzie, stumbles into a baffling mystery. A deceased spiritualist named Johnson apparently vanishes from the mortuary, only to be discovered hanging from a distant chandelier by a roller towel. Unwilling to leave the case to indifferent staff, Tish takes charge, dragging her reluctant companions into late-night investigations, secret explorations of locked rooms, and unexpected encounters with staff members like the nervous little nurse, Miss Blake, and the cheerful Miss Smith. As strange occurrences multiply, including missing bodies, suspicious footprints, and a bizarre series of events involving a supposed runaway ape and slaughtered laboratory animals, the trio pushes deeper into the puzzle.
Tish's relentless logic clashes with Aggie's romantic superstition, while Dr. Tommy Andrews tries to manage both the medical emergencies and his own growing affection for the troubled Miss Blake. When another tragedy strikes with the death of the orderly Briggs, the tension reaches its breaking point, forcing the friends to confront the terrifying reality hidden beneath the hospital's calm facade. Through clever deduction and sheer force of will, Tish gradually untangles the web of secrets, revealing a startling truth about human folly, hidden identities, and devotion.
