I shall be there awaiting your arrival."
"You mean that you will go there alone? I do not understand," the ambassador protested. "Why should I go to my club? I do not at all understand!"
"Nevertheless, do as I say," Peter insisted. "For the present, excuse me. I must look after my guests."
The music had ceased, there was a movement towards the supper room. Peter offered his arm to Madame de Lamborne, who welcomed him with a brilliant smile. Her husband, although, for a Frenchman, he was by no means of a jealous disposition, was conscious of a vague feeling of uneasiness as he watched them pass out of the room together. A few minutes later he made his excuses to his wife, and, with a reluctance for which he could scarcely account, left the house. There was something in the air, he felt, which he did not understand. He would not have admitted it to himself, but he more than half divined the truth. The vacant seat in his wife's carriage was filled that night by the Baron de Grost.
At one o'clock precisely Monsieur de Lamborne returned to his house, and found de Grost gazing with obvious respect at the ponderous safe let into the wall.
"A very fine affair—this," he remarked, motioning with his head towards it.
"The best of its kind," Monsieur de Lamborne admitted. "No burglar yet has ever succeeded in opening one of its type. Here is the packet," he added, drawing the document from his pocket. "You shall see me place it in safety."
Peter stretched out his hand and examined the sealed envelope for a moment closely. Then he moved to the writing-table, and, placing it upon the letter scales, made a note of its exact weight. Finally he watched it deposited in the ponderous safe, suggested the word to which the lock was set, and closed the door. Monsieur de Lamborne heaved a sigh of relief.
"I fancy this time," he said, "that our friends at Berlin will be disappointed. Couch or easy-chair, Baron?"
"The couch, if you please," Peter replied, "a strong cigar, and a long whisky and soda. So! Now for our vigil."
The hours crawled away. Once Peter sat up and listened.
"Any rats about?" he inquired.
The ambassador was indignant.
"I have never heard one in my life," he answered. "This is quite a modern house."
Peter dropped his match-box and stooped to pick it up.
"Any lights on anywhere except in this room?" he asked.
"Certainly not," Monsieur de Lamborne answered. "It is past three o'clock, and every one has gone to bed."
Peter rose and softly unbolted the door. The passage outside was in darkness. He listened intently for a moment, and returned yawning.
"One fancies things," he murmured apologetically.
"For example?" de Lamborne demanded.
Peter shook his head.
"One mistakes," he said. "The nerves become over-sensitive."
The dawn broke, and the awakening hum of the city grew louder and louder. Peter rose and stretched himself.
"Your servants are moving about in the house," he remarked. "I think that we might consider our vigil at an end."
Monsieur de Lamborne rose with alacrity.
"My friend," he said, "I feel that I have made false pretences to you. With the day I have no fear. A thousand pardons for your sleepless night."
"My sleepless night counts for nothing," Peter assured him; "but before I go, would it not be as well that we glance together inside the safe?"
De Lamborne shook out his keys.
"I was about to suggest it," he replied.
The ambassador arranged the combination and pressed the lever. Slowly the great door swung back. The two men peered in.
"Untouched!" de Lamborne exclaimed, a little note of triumph in his tone.
Peter said nothing, but held out his hand.
"Permit me," he interposed.
De Lamborne was conscious of a faint sense of uneasiness. His companion walked across the room and carefully weighed the packet.
"Well?" de Lamborne cried. "Why do you do that? What is wrong?"
Peter turned and faced him.
"My friend," he said, "this is not the same packet."
The ambassador stared at him incredulously.
"This packet can scarcely have gained two ounces in the night," Peter went on. "Besides, the seal is fuller. I have an eye for these details."
De Lamborne leaned against the back of the table. His eyes were a little wild, but he laughed hoarsely.
"We fight, then, against the creatures of another world," he declared. "No human being could have opened that safe last night."
Peter hesitated.
"Monsieur de Lamborne," he said, "the room adjoining is your wife's?"
"It is the salon of madame," the Ambassador admitted.
"What are the electrical appliances doing there?" Peter demanded. "Don't look at me like that, de Lamborne. Remember that I was here before you arrived."
"My wife takes an electric massage every day," Monsieur de Lamborne answered in a hard, unnatural voice. "In what way is Monsieur le Baron concerned in my wife's doings?"
"I think that there need be no answer to that question," Peter said quietly. "It is a greater tragedy which we have to face. I maintain that your safe was entered from that room. A search will prove it."
"There will be no search there," de Lamborne declared fiercely. "I am the ambassador of France, and my power under this roof is absolute. I say that you shall not cross that threshold."
Peter's expression did not change. Only his hands were suddenly outstretched with a curious gesture—the four fingers were raised, the thumbs depressed. Monsieur de Lamborne collapsed.
"I submit," he muttered. "It is you who are the master. Search where you will."
"Monsieur has arrived?" the woman demanded breathlessly.
The proprietor of the restaurant himself bowed a reply. His client was evidently well known to him.
"Monsieur has ascended some few minutes ago."
The woman drew a little sigh of relief. A vague misgiving had troubled her during the last few hours. She raised her veil as she mounted the narrow staircase which led to the one private room at the Hôtel de Lorraine. Here she was safe; one more exploit accomplished, one more roll of notes for the hungry fingers of her dress-maker.
She entered, without tapping, the room at the head
