erkeley 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."

Her red lips parted in a scornful smile.

"Oh, you make me tired," she retorted. "Good-bye, Mr. Foyle."

"Pardon me," he said, and thrusting a couple of fingers into his
waistcoat pocket, fished out a piece of paper. "Do you know this
writing?"

She handed the piece