All Maxfield superstores have sixteen marked aisles. Never seventeen. And at no point should an aisle be barren of product. When fifteen-year-old Mary Gasseling finds aisle 17 empty, she's surprised. For one, her father, who manages the store, would never allow this to happen and two, the aisle seems to have suddenly appeared out of nowhere. Mary soon realizes that the aisle is anything but normal. Struggling with her mother's sudden death two years ago, Mary avoids being home alone by visiting her mother's grave after school before going to her father's store to help. The old caretaker, Horace, even sets out a folding chair she's such a frequent visitor. Little does Mary know the connection between the mysterious aisle and the cemetery she frequents will put her in great danger.