Nikasti, with a low bow, watched the disappearance of the lift into which his two new masters, James Van Teyl and Oscar Fischer, had stepped. He waited until the indicator registered its safe arrival on the ground floor. Then he slowly retraced his steps along the corridor, entered the sitting-room, and took up the telephone receiver, which was still lying upon the table.

"Will you give me number 77," he asked—"Miss Van Teyl's suite?"

There was a moment's silence—then a voice at the other end to which he made obeisance.

"It is Miss Van Teyl who speaks? I am Mr. Van Teyl's valet. Mr. Van
Teyl is here now and will be glad if you will come in."

He replaced the receiver, listened and waited. In a few moments there was the sound of a light footstep outside. The door was opened and Pamela entered. She was still wearing the grey tailor-made costume in which she had left the steamer.

"Why, where is Mr. Van Teyl?" she asked, looking around the room. "I have been ringing up for the last ten minutes and couldn't get any answer. I did not realise that it was the next suite."

"Mr. Van Teyl is close at hand, madam," Nikasti replied. "If you will kindly be seated, I will fetch him."

"How long have you been valet here?" Pamela asked curiously.

"For a few hours only, madam," was the grave reply. "If you will be so good as to wait."

He bowed low and left the room. Pamela took up an evening paper and for a few minutes buried herself in its contents. Then suddenly she held it away from her and listened. A queer and unaccountable impulse inspired her with a certain mistrust. There was no sound of movement in the adjoining bedchamber, nor any sign of her brother's presence. She opened the door and peered in. It was empty and in darkness. Then, moved by that same unaccountable impulse, she crossed the room and listened at the door which led into her own suite, and which she perceived was bolted on this side as well as her own. She listened at first idly, afterwards breathlessly. In a few moments she was convinced that her senses were not playing her false. Some one was moving stealthily about in her room, the key to which was even at that moment in her hand. She hastened to the door, to be confronted by another surprise. The handle turned but the door refused to open. She was locked in.

Pamela was both generous and insistent in the matter of bells. She found four, and she rang them all together. The consequences were speedy, and in their way satisfactory. Nikasti himself, a breathless chambermaid, a hurt but dignified waiter, and the floor valet, who had not even stopped to put on his coat, entered together. They seemed a little stupefied at finding Pamela alone and no sign of any disturbance.

"Why was I locked in here?" Pamela demanded indignantly, taking them en bloc.

There was a little chorus of non-comprehension. Nikasti stepped forward, waved to the others to be silent, and bowed almost to the ground.

"It was a mistake easily to be understood, madam," he explained. "The handle is a little stiff, perhaps, but the door was not locked. We all reached here together, I myself barely a yard in advance. No key was used—and behold!"

Pamela was disposed to argue, but a moment's reflection induced her to change her mind. This falsehood of Nikasti's was at least interesting. She waved the hotel servants away.

"I am sorry to have troubled you," she said. "I will remember it when I pay my bill."

They took their leave, Nikasti showing them out. When the last had departed, he turned back to the centre table, from the other side of which Pamela was watching him curiously.

"I cannot imagine," she remarked, "how I could have made such a mistake about the door. I tried it twice or three times and it certainly seemed to me to be locked."

Nikasti moved a step nearer towards her. Something of the servility of his manner had gone. For the first time she looked at him closely, appreciated the tense immobility of his features, the still, penetrating light of his cold eyes. A queer premonition of trouble for a moment unsteadied her.

"There was no mistake," he said softly. "The door was locked."

Even then she did not fully understand the position. She leaned a little towards him.

"It was locked?" she repeated.

"I locked it," he told her. "It is locked now, securely. I have been searching in your room for something which I did not find. I think that you had better give it to me. It will save trouble."

"Are you mad?" she demanded breathlessly.

"Do I seem so?" he replied. "There is no person more sane than I. I require from you the formula of the new explosive, which you stole in Henry's restaurant eleven days ago."

The sense of mystery passed. It was simply trouble of the ordinary sort from an unexpected source.

"Dear me!" she murmured. "Every one seems interested in my little adventure. How did you hear about it?"

"I destroyed the cable telling me of all that happened only a few minutes ago," he explained. "It was the foolish talk of the young inventor which gave his secret to the world to scramble for."

"It was very clever of your informant," she remarked, "to suggest that I was the fortunate thief. Why not Oscar Fischer? It was his plot, not mine."

The eyes of the little Japanese seemed suddenly to narrow. He realised quite well that she was talking simply to gain time.

"Madam," he insisted, "the formula. It is for my country, and for my country I would risk much."

"I do not doubt it," she replied; "but if I hold it, I hold it for my country, too, and there is nothing you would risk for Japan from which I should shrink for America."

He laid his hands upon the table. She turned her ring and clenched her hand. She could see his spring coming, realised in those few seconds that here was an opponent of more desperate and subtle calibre than Joseph. Whether her wits might have failed her, fate remained her friend. There was a knock at the door.

"You hear?" she cried breathlessly. "There is some one there. Shall I call out?"

His hands and knee were gone from the table. He was once more his old self, so completely the servant that for a moment even Pamela was puzzled. It seemed as though the events of the last few seconds might have been part of a disordered dream. Nikasti played to the cue of her fevered question and entirely ignored them. He opened the door with a respectful flourish—and John Lutchester walked in.