When Minty discovers a mysterious sundial, she is thrust into a temporal rift that bridges the gap between her present and a haunting, fractured past. Minty finds herself navigating a world where the boundaries of time are porous, allowing her to interact with figures from different eras. Her primary objective is to understand the nature of the voices she hears and the strange occurrences surrounding the sundial, all while contending with the malevolent influence of Miss Vole. The narrative unfolds through a third-person perspective that emphasizes the atmospheric shift between the modern day and the historical settings Minty visits.

Readers frequently highlight the eerie, atmospheric quality of the prose which effectively captures a sense of historical displacement. Discussion often centers on the effectiveness of the time-slip device as a means to explore themes of memory and hidden history. Critics note that the pacing remains steady, balancing the protagonist's internal confusion with the external threats posed by the antagonist. The work is often praised for its ability to maintain tension without relying on excessive action, focusing instead on the psychological impact of the supernatural events on the young protagonist.