“Quite correct.”

“This morning a housemaid discovered the body at approximately 7.45 A.M. Dr. Cartwright examined the dead man and found that death was the result of a bullet fired from a revolver. No revolver was found, and no one in the house seems to have heard the shot. On the other hand the dead man’s wrist watch was smashed by the fall, and marks the crime as having been committed at exactly a quarter to twelve. Now what time did you retire to bed last night?”