Connie Bowskill should be asleep. Instead, she's logging on to a property website in search of a particular house: 11 Bentley Grove, Cambridge. She knows it's for sale; there is an estate agent's board in the front garden. Soon Connie is clicking on the "Virtual Tour" button, keen to see the inside and put her mind at rest once and for all. She finds herself looking at a scene from a nightmare: in the living room, in the middle of the carpet, a woman lies face down in a huge pool of blood. In shock, Connie wakes her husband Kit. But when Kit sits down at the computer, he sees no dead body, only a pristine beige carpet in a perfectly ordinary room...