内容简介：
The man in the corner pushed aside his glass, and leant across the table. "Mysteries " he commented. "There is no such thing as a mystery in connection with any crime, provided intelligence is brought to bear upon its investigation." Very much astonished Polly Burton looked over the top of her newspaper, and fixed a pair of very severe, coldly inquiring brown eyes upon him. She had disapproved of the man from the instant when he shuffled across the shop and sat down opposite to her, at the same marble-topped table which already held her large coffee (3d.), her roll and butter (2d.), and plate of tongue (6d.).