Elizabeth Bell runs a quiet household, with no family and no more than the usual number of servants. She passes her time thinking about crime and working on her biography of a relative. When a young cousin comes to stay, life in the house becomes uncharacteristically lively. First, cousin Judy burns a hole in Miss Bell's desk. Next, they spy a burglar on the staircase--a shadowy figure who vanishes without a trace. And finally, Sarah, the nurse, takes the dogs for a walk and never returns.

But these mysterious goings-on take a dark turn when the vanished woman is found savagely murdered. According to the police, the killer must be part of the household, a fact which Ms. Bell struggles to believe. That is until more deaths follow, and the entire staff begins to look more threatening than the old lady ever could have imagined.

An atmospheric whodunit bursting with family secrets and period details, The Door exemplifies the sort of aristocratic intrigue that made Mary Roberts Rinehart one of the bestselling and most beloved authors of her day.