“Do I? Let me tell you: the rooms are full of detectives, male and female. The chief of the Secret Police is a man of genius, a Swiss called Krantz. He speaks seven languages and seems to have an eighth sense, the sense of detection. You may have seen him, a tall, thin man dressed in black with a dark, clean-shaven face. He always wears a smile of cheerful simplicity.”

“And Bob?”

“Oh, Bob’s just a spy. He keeps track of the English crooks and shadows if required. They say Krantz values him.”

“It seems very strange to me.”

“Not at all. If you only knew the underground workings of this place, the mentality, the way in which everything is run.... Why, here you’re not living in the Twentieth Century at all. It’s mediæval. Even now some spy may be trying to over-hear us.”

“A queer place!”

“Yes, and packed with the queerest people on earth. Now, for instance, that little girl in black, just entering.”

Hugh started. The girl was Margot Leblanc. He had not seen her for some time, and had wondered if she was still at the pension. She was dressed shabbily and as she passed he saw that her face was white and haggard, and her eyes stared vacantly before her. She sat down at a nearby table.

“Now, that girl,” continued Mr. Tope, “is a puzzle to me. She came here about two months ago and she has never been seen to speak to any one. She is always alone. Nobody knows anything about her. She spends most of her time in the Rooms gambling with small stakes. I have seen her stand silently at a table for hours.... By the way, here come my friends, the Calderbrooks. Let me introduce you.”

The Calderbrooks were so uncompromisingly English, that their nationality was recognizable a long way off. They wore tailored costumes made of the same kind of tweed, with stockings of wool and low tan shoes. Under broad-brimmed hats their faces were pink and cheerful. The mother was sweet; the girl pretty; the father a tall thin man, with drooping moustache, a mild manner, and pale blue eyes.