But it was not to Berkeley Square that he telephoned from the privacy of the divisional C.I.D. offices. It was to Scotland Yard. Within five minutes Chief Inspector Green was setting out from the great red-brick building to see, first, the Duke of Burghley and, secondly, Lady Eileen Meredith. A full hour passed away, and Foyle received the result of the inquiries into Petrovska's movements. Her alibi was complete. In every particular her story of her movements had proved right.
Green, arriving at the police station with an agitated and puzzled nobleman and his solicitor, saw his chief for a few moments alone.
"She admits having handed over the jewels to Lola, but she won't say a word beyond that," he said. "She's as obstinate as a mule. I have told the Duke something of where we stand, and he has agreed to take the gems back without letting her know. It was a tough job, but I got him to see at last that the girl might be implicating herself. He says he's never heard of Petrovska."
"H'm." Foyle rubbed his chin vigorously. "I'll have a talk with the old boy. See if you can get the Public Carriage Office to borrow us a taxicab, and get Poole to drive it slowly up and down this street. If she hails it when she goes out, well and good. If not, Bolt and you had better follow her, and the cab will come after you so that you can use it in emergency."
Green had done his work with the Duke and the lawyer with tact. Foyle found his interview with them confined to evading questions that he had no wish to answer. He dismissed them at last with the jewels in the custody of the man of the law. Then he went straight to his prisoner.
"You can go," he said abruptly. "I shall ask you to be very careful, however, Princess. If you are wise you will leave England at once."
"Why?" she asked, opening her blue eyes wide and gazing at him with blank astonishment.
His voice became silky.
"Because, my dear lady," he said, "I feel that your career in England may not be altogether without reproach. I shall try to find out a little more about it, and if I get a chance, I warn you frankly, I shall have you taken into custody. You are too mischievous to be allowed to run around loose."