The hall-porter opened the door at a sign from his imperious master, and the valet went out with a slow, stealthy tread. He followed in the wake of Corsini, who marched along gaily, his violin-case swinging from his hand, his thoughts full of the Princess Nada, who had been so sweet to him, so gracious. He hummed one of the gayest of the many gay airs from "Il Barbiere" as he walked along. It was one of his favourite operas, one in which La Belle Quéro was inimitable. He was in a very happy frame of mind to-night as he walked through the silent streets. He even thought tenderly of La Belle Quéro, and went to the length of forgiving her for what he had once considered her groundless jealousy of the Princess. In the midst of these happy thoughts, four black shadows loomed up against him, four men surrounded him. What a fool he had been not to take the Princess's advice and drive home! St. Petersburg, like every other populous city, was full of thieves. Blindly he struck out with his disengaged hand. Shrilly he called out for help. One of the burly men who had surrounded him threw a handkerchief over his face. In a few seconds his struggles had ceased. His almost inanimate form was conveyed to the waiting carriage, standing in a side street not far from the Zouroff Palace. It was bundled inside, two of the men mounted the box, the others sat inside, and the horses set off at a fast trot in the direction of the Moscow road. The valet, Peter, strolled back home. His master was lounging about in the vestibule to await the news. Peter whispered them in his ear. Zouroff smiled a slow smile of gratified malice. "The bird is trapped," he exulted as he ascended the staircase, to mingle once more with his guests. CHAPTER XVI After having delivered her letter in the way recorded in a previous chapter, Katerina had sped away with the swiftness of the proverbial arrow. She was well on her way home before it reached the hands of General Beilski, who was closeted with an official of high importance and could not be disturbed till the interview was finished. The Chief of Police was, above all things, a man of action. There was nothing in the letter itself to give the least clue as to the writer, but it was evidently genuine. He came to the conclusion that the woman who had sent it was unwillingly mixed up in some plot against which her conscience revolted. He immediately called in one of his subordinates to make arrangements for the immediate despatch of a body of mounted police to Pavlovsk, where they would lie in wait for the arriving carriage.