From one of his friends in London he had had secret warning that the police, on the day he left Charing Cross, had descended upon Shapley Manor and had arrested Mrs. Bond under a warrant applied for by the French police, and he also knew that her extradition for trial in Paris had been granted.

That there was a traitor in the camp was proved, but happily Hugh Henfrey had escaped just in time.

For himself The Sparrow cared little.  He seemed to be immune from arrest, so cleverly did he disguise his true identity; yet now that some person had revealed his secrets, what more likely than the person, whoever it was, would also give him away for the sake of the big reward which he knew was offered for his apprehension.

Before leaving Paris that evening he had dispatched a telegram, a reply to which was handed him in the train when it stopped at Lyons early next morning.

This decided him.  He sent another telegram and then returned to where Hugh was lying half awake.  When they stopped at Marseilles, both men were careful not to leave the train, but continued in it, arriving at the great station of Nice in the early afternoon.

They left their bags at a small hotel just outside the station, and taking a cab, they drove away into the old town.  Afterwards they proceeded on foot to the Rue Rossetti, where they climbed to the flat occupied by old Giulio Cataldi.

The old fellow was out, but the elderly Italian woman who kept house for him said she expected him back at any moment.  He was due to come off duty at the cafe where he was employed.

So Hugh and his companion waited, examining the poorly-furnished little room.

Now The Sparrow entertained a strong suspicion that Cataldi knew more of the tragedy at the Villa Amette than anyone else.  Indeed, of late, it had more than once crossed his mind that he might be the actual culprit.

At last the door opened and the old man entered, surprised to find himself in the presence of the master criminal, The Sparrow, whom he had only met once before.

He greeted his visitors rather timidly.

After a short chat The Sparrow, who had offered the old man a cigarette from a cheap plated case much worn, began to make certain inquiries.

“This is a very serious and confidential affair, Cataldi,” he said.  “I want to know the absolute truth—­and I must have it.”

“I know it is serious, signore,” replied the old man, much perturbed by the unexpected visit of the king of the underworld, the elusive Sparrow of whom everyone spoke in awe.  “But I only know one or two facts.  I recognize Signor Henfrey.”

“Ah!  Then you know me!” exclaimed Hugh.  “You recognized me on that night at the Villa Amette, when you opened the door to me.”

“I do, signore.  I recollect everything.  It is all photographed upon my memory.  Poor Mademoiselle!  You questioned her—­as a gentleman would—­and you demanded to know about your father’s death.  She prevaricated—­and——­”