""It's a big thing,"" said Loveday Brooke, addressing Ebenezer Dyer, chief of the well-known detective agency in Lynch Court, Fleet Street; ""Lady Cathrow has lost GBP30,000 worth of jewellery, if the newspaper accounts are to be trusted."" ""They are fairly accurate this time. The robbery differs in few respects from the usual run of country-house robberies. The time chosen, of course, was the dinner-hour, when the family and guests were at table and the servants not on duty were amusing themselves in their own quarters. The fact of its being Christmas Eve would also of necessity add to the business and consequent distraction of the household. The entry to the house, however, in this case was not effected in the usual manner by a ladder to the dressing-room window, but through the window of a room on the ground floor - a small room with one window and two doors, one of which opens into the hall, and the other into a passage that leads by the back stairs to the bedroom floor....""