The Princess had half risen and gave a little cry of dismay at the intrusion. With grim, set face the detective adjusted his tall form to the limits of the cab and sat down beside her. His hand encircled her wrist, and he forced her back to the seat.

"I shouldn't try to open the door if I were you," he said quietly. "You might fall out."

The woman dropped back and did some quick thinking. She had no difficulty in guessing who Foyle was, and she could scarcely have failed to see the staring figure of the butler as she left the Duke of Burghley's house. She fenced for time, doing the astonished, outraged, half-frightened innocent to perfection.

"What does this mean? How dare you molest me? Where are you taking me?"

The detective smiled easily as he answered in the formal words of C.I.D.

custom: "I am a police officer--perhaps I needn't tell you that--and I am taking you to Malchester Row Police Station."

"To arrest me? You would dare? Do you know I am the Princess Petrovska?

There is some mistake. I shall appeal to the Russian Amba.s.sador. What do you say I have done? I am a friend of Lady Eileen Meredith, the daughter of the Duke of Burghley. She will tell you I have only just left her.

You are confusing me with some one else."

It was admirably done. The mixture of indignation and haughtiness might have imposed upon some people, and the threat of appeal to the Russian Amba.s.sador had been very adroit. Heldon Foyle merely nodded.

"This is not arrest," he replied. "It is not even detention--unless you force me to it. I am inviting you to accompany me to give an account of your movements on the night that Harry Goldenburg was murdered. I will call your bluff, Lola, and we will call at the amba.s.sador's if you like."

She made a gesture with one hand, as of a fencer acknowledging a hit, and, turning her head, smiled sweetly into his face. Nevertheless, in spite of everything, she felt a little nervous. She had gone to see Eileen with her eyes not fully open to the risk she ran. Deftly used, newspapers have their uses. In supplying the story of the murder to the pressmen, Foyle had omitted all mention of the finding of the miniature.

The woman had not known that Scotland Yard had a portrait of her, and had deemed it unlikely that she would be recognised by the watchers of the house. Although she had lived by her wits in many quarters of the world, she had hitherto avoided trouble with the police in England. She wondered how much Foyle knew. It was evidently of no use trying to impress him with the importance of her rank and connections. Princesses are cheap in Russia.

"You are Mr. Heldon Foyle, of course," she said. "I have heard that you are very clever. I don't see what I can have had to do with the murder, even if I am Lola Rachael--which I admit."

"We shall see. Can you prove where you were between ten o'clock, when you left the Palatial Hotel, and midnight on that date?"

She laughed merrily. "You are not so clever as I thought," she exclaimed. "Do you think that I am a murderess? I went straight to an hotel near Charing Cross--the Splendid--and caught the nine o'clock boat train to Paris. It is easily proved."

Foyle shifted to the seat opposite, so that he could see her face more easily.

"Then you don't deny that you visited Grosvenor Gardens that night, that you were admitted by Ivan Abramovitch, Grell's valet, and taken to his study?"

"Of course I do," she retorted laughingly. "If that's all you've got to go upon you may as well let me go now."

"Very well. We shall see," he answered.

The cab stopped at Malchester Row Police Station.

CHAPTER XXI

To the constable who opened the cab door Foyle gave quick instructions in a low voice. The Princess Petrovska found herself ushered into a plainly furnished waiting room, decorated with half-a-dozen photographic enlargements of the portraits of high police officials and a photogravure of "Her Majesty the Baby." There the policeman left her.

Foyle came to her a moment later. His couple of questions to the cabman as he paid him had not been fruitful. He had been ordered by the lady to drive to Waterloo Station. It was a fairly obvious ruse, which would have had the effect of effectually confusing her trail, for from there she might have taken train, tube, omnibus, tram, or cab again to about any point in London.

"I am sorry," he apologised. "We shall have to keep you here for an hour or two while your statements are verified."

"I don't mind," she countered lightly. "It will be an amusing experience. I have never seen a police station before. Perhaps you would like to show me over while we're waiting, Mr. Foyle."

The superintendent was admiring her confidence a little ruefully. A pleasant-faced, buxom woman tapped at the door, and Lola eyed her with misgivings. Foyle's blue eyes were fixed on her face.

"I am afraid I must deny myself that pleasure," he said suavely. "There are other matters which will take up our time. First, I shall be obliged if you will let the matron here search you."

The nonchalance of the Princess Petrovska had disappeared in a flash, and Foyle noted her quick change of countenance. She had recollected she was carrying Lady Eileen Meredith's jewels. They would inevitably be found, if she were searched. She was not so much worried by what explanation she could give as to what would be the result of a questioning of Eileen. Angrily defiant, she was on her feet in a flash.

"You have no right to search me. I am not under arrest," she declared.

Foyle knew she was right. What he was doing was flagrantly unlawful unless he charged her with some offence. Yet there are times when it is necessary for a police officer to put a blind eye to the telescope and to do technically illegal things in order that justice may not be defeated. This he felt was one of the occasions. He ignored her protestations and left the room, closing the door after him. For a brief moment the woman forgot the breeding of the Princess Petrovska in the fiery pa.s.sion of Lola the dancer. But if she meditated resistance, a second's reflection convinced her that it would be futile. The matron, for all her good-tempered face, was well developed muscularly, and did not seem the kind of woman to be trifled with. The Princess submitted with as good a grace as she could muster.

As the woman drew forth the casket of jewels Lola made one false move.

She laid a slim-gloved hand on her arm.

"If you want to earn ten pounds you will give me that back," she said softly.

The matron shook her head with so resolute an expression that the word "twenty," which trembled on the Princess Petrovska's lips, was never uttered. Gathering in her hands the articles she had found, she stepped outside. In three minutes her place was taken by Foyle. He quietly returned to her everything but the jewel case. This he held between his fingers.

"Where did you get this?" he demanded. His voice was keyed to the stern, official tone he knew so well how to a.s.sume.

She gripped the side of a chair tightly.

"What is that to do with you? It is mine. Give it to me."

"Not unless you can prove it is yours. If you do not, I shall charge you with being in possession of property suspected to be stolen."

She bit her lips until the blood came. Her face had become very pale. If the threat were meant seriously--and she could see no reason why it should not be--she was in an awkward predicament. Ordinarily she had ready resource, a fertile genius for invention. Now her wits seemed to have deserted her. Cudgel her brains as she would, she could see no way out of the difficulty. To boldly state that the jewels had been entrusted to her by Eileen would involve opening up a fresh line of inquiry for the C.I.D. men that might have disastrous results. Nor was there any person who might bear out a story invented on the spur of the moment.

"Well?" He spoke coldly.

"I refuse to tell you where I got them," she retorted. "You must do as you like."

"Then it is my duty to warn you that anything you say may be used in evidence against you. You will be charged." He opened the door and cried down the corridor, "Reserve!" To the constable who answered he indicated the Princess by a nod. "Take this woman to the detention room. She will be paraded for identification in half an hour."

The detention room of a London police station is a compromise between the comparative luxury of a waiting-room and the harshness of a cell.

Like a waiting-room it is furnished with chairs and tables, and like a cell its door is provided with a strong, self-acting lock. The Princess Petrovska gritted her teeth viciously as she was left alone, and paid no heed to the magazines and papers left on the table--a consideration for visitors that had not been discernible in the waiting-room.

Meanwhile, Foyle had set every available man of the divisional detachment of the C.I.D. busily at work. A couple had been sent to verify the account given by the woman of her movements on the night when the murder occurred. The remainder had been sent to bring in a score of women, the wives and daughters of inspectors and other senior officers.

Detective-Inspector Taylor had turned up with Wills, who was informed of the part he had to play.

"You say you couldn't recognise the woman who came out of Lord Burghley's house. Now we're going to give you another try. We don't want you to pick any one out unless you're absolutely sure. Mind that."

Some of the women who had been fetched in by the detectives were rejected by Foyle as being too unlike the Princess. He intended the identification test to be as fair as possible. The ten who finally took their places in the high-pitched charge room were as nearly like the Princess in build and dress as could be managed from the choice afforded. They stood in a row on the opposite side of the room from the steel-railed dock and the high desk. Then Lola was brought in. Her head was held high, and her lips curled superciliously as she took in the arrangements.

"Please choose a position among these ladies," said Foyle urbanely. "You may stand anywhere you like."

There was an angry glitter in her dark eyes as she obeyed. She was not the sort of woman to risk a scene uselessly. Then Wills was brought in.

Foyle put a formal question to him.