Heldon Foyle's eyes lingered in quiet scrutiny on the other's face.

"I shall do what I consider to be my duty," he said, his voice a little hard. "Come, Sir Ralph, you will see I must do my best to bring the murderer of this man to justice. Had Mr. Grell any relations?"

"I don't believe there's one in the wide world."

"And you don't remember what time he left? Try, Sir Ralph. It is important. Before you came I sent a man to the club, and none of the servants recollects seeing either of you go. They say he was with you most of the evening. You can clear up this matter of time."

"I don't remember what time he left me."

The baronet's voice was hoa.r.s.e and strained. Foyle rose and stood towering over him.

"You are lying," he said deliberately.

Sir Ralph recoiled as though he had been struck in the face. A quick wave of crimson had mounted to his temples. Instinctively his hands clenched. Then regaining a little control of himself he wheeled about without a word. His hand was on the handle of the door when the superintendent's suave voice brought him to a halt.

"Oh, by the way, Sir Ralph, you might look at this before you go, and say whether you recognise it."

He held his clenched hand out, and suddenly unclasped it to disclose the miniature set in diamonds.

Sir Ralph gave a start. "By Jove, it's little Lola of Vienna!" he exclaimed. Then realised that he had been trapped. "But I shall tell you nothing about her," he snapped.

"Thank you, Sir Ralph," said the other quietly.

"But this I think it right you should know," went on Fairfield, standing with one hand still on the handle of the door: "When Grell was with me last night he showed me a pearl necklace, which he said he had bought as a wedding present for Lady Eileen Meredith. If you have not found it, it may give you some motive for the tragedy."

"Ah!" said Foyle unemotionally.

CHAPTER V

Day had long dawned ere Foyle and his staff had finished their work at the great house in Grosvenor Gardens. There had been much to do, for every person who might possibly throw a light on the tragedy had to be questioned and requestioned. The place had been thoroughly searched from attic to cellar, for letters or for the jewels that, if Sir Ralph Fairfield were right, were missing.

Much more there would be to do, but for the moment they could go no further. Foyle returned wearily to Scotland Yard to learn that of the finger-prints on the dagger two were too blurred to serve for purposes of identification. He ordered the miniature to be photographed, and held a short consultation with the a.s.sistant commissioner. The watch kept for Ivan had so far been without avail. In the corridor, early as it was, a dozen journalists were waiting. Foyle submitted good-humouredly to their questions as they grouped themselves about his room.

"Yes. Of course, I'll let you know all about it," he protested. "I'll have the facts typed out for you, and you can embroider them yourselves.

There's a description of a man we'd like to get hold of--not necessarily the murderer, but he might be an important witness. Be sure and put that in."

He always had an air of engaging candour when dealing with newspaper men. Sometimes they were useful, and he never failed to supply them with just as much information about a case as would in any event leak out.

That saved them trouble and made them grateful. He went away now to have the bare details of the murder put into shape. When he returned he held the diamond-set miniature in his hand.

"This has been left at the Lost Property Office," he declared unblushingly. "It's pretty valuable, so they've put it into our hands to find the owner. Any of you boys know the lady?"

Some of them examined it with polite interest. They were more concerned with the murder of a famous man. Lost trinkets were small beer at such time. Only Jerrold of _The Wire_ made any suggestion.

"Reminds me of that Russian princess woman who's been staying at the Palatial, only it's too young for her. What's her name?--Petrovska, I think."

"Thanks," said Foyle; "it doesn't matter much. Ah, here's your stuff.

Good-bye, boys, and don't worry me more than you can help. This thing is going to keep us pretty busy."

He saw them out of the room and carefully closed the door. Sitting at his desk he lifted the receiver from the telephone.

"Get the Palatial Hotel," he ordered. "h.e.l.lo! That the Palatial? Is the Princess Petrovska there? What? Left last night at ten o'clock? Did she say where she was going? No, I see. Good-bye."

He scribbled a few words on a slip of paper, and touching the bell gave it to the man who answered. "Send that to St. Petersburg at once."

It was a communication to the Chief of the Russian police, asking that inquiries should be made as to the antecedents of the Princess.

For the next three hours men were coming rapidly in and out of the superintendent's office, receiving instructions and making reports.

Practically the whole of the six hundred men of the C.I.D. were engaged on the case, for there was no avenue of investigation so slender but that there might be something at the end of it. Neither Foyle nor his lieutenants were men to leave anything to chance. Green was seated opposite to him, discussing the progress they had made.

The superintendent leaned back wearily in his chair. Some one handed him a slim envelope. He tore it open and slowly studied the cipher in which the message was written. It read--

"Silinsky, Chief of Police, St. Petersburg. To Foyle, Superintendent C.I.D., London.

"Woman you mention formerly Lola Rachael, believed born Paris; formerly on stage, Vienna; married Prince Petrovska, 1898. Husband died suddenly 1900. Travels much. No further particulars known."

Foyle stroked his chin gravely. "Formerly Lola Rachael," he murmured.

"And Sir Ralph recognised the miniature as little Lola of Vienna. She's worth looking after. We must find her, Green. What about this man Ivan?"

"No trace of him yet, sir, but I don't think he can give us the slip.

He hadn't much time to get away. By the way, sir, what do you think of Sir Ralph?"

"I don't know. He's keeping something back for some reason. You'd better have him shadowed, Green. Go yourself, and take a good man with you. He mustn't be let out of sight night or day. I may tackle him again later on."

"Very good, sir. Waverley's still at Grosvenor Gardens. Will you be going back there?"

"I don't know. I want to look through the records of the Convict Supervision Office for the last ten years. I have an idea that I may strike something."

Green was too wise a man to ask questions of his chief. He slipped from the room. Half an hour later Foyle dashed out of the room hatless, and, picking up a taxicab, drove at top speed to Grosvenor Gardens. He was greeted at the door by Lomont.

"What is it?" he demanded, the excitement of the detective communicating itself to him. "Have you carried the case any further?"

"I don't know," replied the detective. "I must see the body again. Come up with me."

In the death-chamber he carefully locked the door. A heavy ink-well stood on the desk. He twisted up a piece of paper and dipped it in.

Then, approaching the murdered man, he smeared the fingers of his right hand with the blackened paper and pressed them lightly on a piece of blotting paper. The secretary, in utter bewilderment, watched him compare the prints with a piece of paper he took from his pocket.

"What is it?" he repeated again.

"Mr. Lomont," replied the detective gravely, "I wish I knew. Unless our whole system of identification is wrong--and that is incredible--that man who lies dead there is not Robert Grell."

CHAPTER VI