Lock Every Door

No guests. No sleeping out of the flat on any evenings. Please don't bother the other residents—all of them are either renowned or wealthy. Jules Larsen's new position as a flat sitter at the Bartholomew, one of Manhattan's most prestigious and enigmatic buildings, has just these regulations. Jules, who has just experienced heartbreak and financial ruin, is overcome by the beauty of her surroundings and agrees to the conditions, prepared to move on from her previous existence.

Jules finds herself attached to Ingrid, a fellow flat sitter, as she gets to know the tenants and staff of the Bartholomew. Ingrid unsettlingly but comfortingly reminds Jules of her sister, who she lost eight years ago. Jules dismisses Ingrid's fearful tale as a lighthearted ghost story when she confides that the Bartholomew is not what it seems and that the sinister past concealed behind its shining exterior is beginning to terrify her—until Ingrid vanishes the next day.

Jules delves more into the Bartholomew's shadowy history and the mysteries concealed behind its walls in an effort to uncover the truth about Ingrid's abduction. After learning that Ingrid is not the only flat sitter at the Bartholomew to disappear, Jules finds herself in a race against time to identify the murderer, uncover the history of the building, and get out of the Bartholomew before her status as a temporary resident changes.