The Duke shut the door and leant against it, listening anxiously, breathing quickly. There came the bang of the front door. With a deep sigh of relief he left the door, came briskly, smiling, across the room, and put the card-case back into the pocket of Guerchard's cloak.

He lighted a cigarette, dropped into an easy chair, and sat waiting with an entirely careless air for the detective's return. Presently he heard quick footsteps on the bare boards of the empty room beyond the opening. Then Guerchard came down the steps and out of the fireplace.

His face wore an expression of extreme perplexity:

"I can't understand it," he said. "I found nothing."

"Nothing?" said the Duke.

"No. Are you sure you saw the handkerchief in one of those little rooms on the second floor--quite sure?" said Guerchard.

"Of course I did," said the Duke. "Isn't it there?"

"No," said Guerchard.

"You can't have looked properly," said the Duke, with a touch of irony in his voice. "If I were you, I should go back and look again."

"No. If I've looked for a thing, I've looked for it. There's no need for me to look a second time. But, all the same, it's rather funny.

Doesn't it strike you as being rather funny, your Grace?" said Guerchard, with a worried air.

"It strikes me as being uncommonly funny," said the Duke, with an ambiguous smile.

Guerchard looked at him with a sudden uneasiness; then he rang the bell.

Bonavent came into the room.

"Mademoiselle Kritchnoff, Bonavent. It's quite time," said Guerchard.

"Mademoiselle Kritchnoff?" said Bonavent, with an air of surprise.

"Yes, it's time that she was taken to the police-station."

"Mademoiselle Kritchnoff has gone, sir," said Bonavent, in a tone of quiet remonstrance.

"Gone? What do you mean by gone?" said Guerchard.

"Gone, sir, gone!" said Bonavent patiently.

"But you're mad.... Mad!" cried Guerchard.

"No, I'm not mad," said Bonavent. "Gone! But who let her go?" cried Guerchard.

"The men at the door," said Bonavent.

"The men at the door," said Guerchard, in a tone of stupefaction. "But she had to have my permit ... my permit on my card! Send the fools up to me!"

Bonavent went to the top of the staircase, and called down it.

Guerchard followed him. Two detectives came hurrying up the stairs and into the drawing-room.

"What the devil do you mean by letting Mademoiselle Kritchnoff leave the house without my permit, written on my card?" cried Guerchard violently.

"But she had your permit, sir, and it WAS written on your card,"

stammered one of the detectives.

"It was? ... it was?" said Guerchard. "Then, by Jove, it was a forgery!"

He stood thoughtful for a moment. Then quietly he told his two men to go back to their post. He did not stir for a minute or two, puzzling it out, seeking light.

Then he came back slowly into the drawing-room and looked uneasily at the Duke. The Duke was sitting in his easy chair, smoking a cigarette with a listless air. Guerchard looked at him, and looked at him, almost as if he now saw him for the first time.

"Well?" said the Duke, "have you sent that poor child off to prison? If I'd done a thing like that I don't think I should sleep very well, M.

Guerchard."

"That poor child has just escaped, by means of a forged permit," said Guerchard very glumly.

"By Jove, I AM glad to hear that!" cried the Duke. "You'll forgive my lack of sympathy, M. Guerchard; but she was such a child."

"Not too young to be Lupin's accomplice," said Guerchard drily.

"You really think she is?" said the Duke, in a tone of doubt.

"I'm sure of it," said Guerchard, with decision; then he added slowly, with a perplexed air:

"But how--how--could she get that forged permit?"

The Duke shook his head, and looked as solemn as an owl. Guerchard looked at him uneasily, went out of the drawing-room, and shut the door.

"How long has Mademoiselle Kritchnoff been gone?" he said to Bonavent.

"Not much more than five minutes," said Bonavent. "She came out from talking to you in the drawing-room--"

"Talking to me in the drawing-room!" exclaimed Guerchard.

"Yes," said Bonavent. "She came out and went straight down the stairs and out of the house."

A faint, sighing gasp came from Guerchard's lips. He dashed into the drawing-room, crossed the room quickly to his cloak, picked it up, took the card-case out of the pocket, and counted the cards in it. Then he looked at the Duke.

The Duke smiled at him, a charming smile, almost caressing.

There seemed to be a lump in Guerchard's throat; he swallowed it loudly.

He put the card-case into the breast-pocket of the coat he was wearing.

Then he cried sharply, "Bonavent! Bonavent!"

Bonavent opened the door, and stood in the doorway.

"You sent off Victoire in the prison-van, I suppose," said Guerchard.

"Oh, a long while ago, sir," said Bonavent.