The table crashed to the floor as Grell, the last remnants of his self-restraint gone, leapt to his feet. Sir Hilary Thornton sprang between the two men. Foyle also had risen, and though his face was impa.s.sive the blue eyes were sparkling and his fists were clenched.

"You liar!" raved Grell. "How dare you bring her name into it!"

"This excitement will not advance matters," said Foyle placidly. "Sit down for a little, Mr. Grell. You cannot prevent the inevitable."

The tense muscles of the prisoner relaxed and a shivering fit shook him from head to foot. He could see the blow that he had striven to avert falling while he stood impotent. He had taken every risk, made every sacrifice man could make, to turn it aside. Now he had been told that he had failed. It was not easy to admit defeat. His debonair courage had gone.

Sir Hilary Thornton laid a hand gently on his shoulder. "My dear Mr.

Grell," he said, "I don't want to use the ordinary cant about duty and all the rest of it. We may sympathise with you--personally, I admire the att.i.tude you have taken, though perhaps I shouldn't say it--but our own feelings do not matter the toss of a b.u.t.ton. Nothing you can do or say will swerve us from what we judge to be the interests of justice."

"Let me alone for a little while," answered Grell dully; "I want to think."

They sent him back to the detention-room where, with a constable seated opposite to him, he was to spend the night. Foyle rested one arm on the mantelpiece and kicked the fire viciously into a blaze.

"Ours is an ungrateful business, Sir Hilary," he grumbled, "but I've never come across a man who put so many difficulties in the way of being saved from the gallows as Mr. Robert Grell."

Thornton took a long breath that was almost a sigh. "Poor chap," he said reflectively. "Poor chap!" And then, after an interval, "Poor girl!

Couldn't you have dropped a hint, Foyle?"

The introduction of sentiment into business was a folly that Heldon Foyle seldom permitted himself. With a shrug he pulled himself together.

He shook his head. "We've got to be more certain yet. I daren't tell him too much--for my idea may prove to be wrong. You must remember that it was undoubtedly Eileen Meredith's finger-prints on the dagger. At present it is only surmise of mine how they got there. Finding the prints on her blotting-pad, which I showed you, corresponded with those on the dagger you gave me, was one of the biggest surprises of my life.

But we may clear it up now."

"H'm," said Thornton. "Well, we shall have to look sharp."

A thought struck Foyle. He stood rigid as a statue for a moment, and then slapped his knee with sudden energy, "By G.o.d! I believe I've got it!" he exclaimed, and jumped for the telephone.

"Put me through to the Yard.... h.e.l.lo! I want Mr. Grant.... That you, Grant?... About the Grosvenor Gardens case. Tell me. Might the finger-prints on the dagger have been caused by some one withdrawing it and replacing it after the murder had been committed? Would the second handling have obliterated first prints?... Blurred them. I see. But if the person who first handled the dagger wore gloves? Thanks. That's what I wanted to know."

He replaced the receiver and turned triumphantly on Thornton. "That bears out my idea, Sir Hilary. Will you excuse me while I see if Bolt's on the premises?"

Without waiting for a reply, he darted from the room. The a.s.sistant Commissioner's brow puckered and he thoughtfully replaced the upset furniture. By the time he had finished Foyle had returned.

"Just caught him," he said. "I've sent him to collect all the men he can find to make some fresh inquiries."

"I'm a little bewildered," confessed Thornton, jingling some money in his trousers pockets and turning blankly upon the superintendent. "Do you think you'll be able to do it--to bring this crime home to the Princess Petrovska?"

"I think I can," replied the superintendent. "I was a blind a.s.s not to see it earlier. Lola's alibi--which is proved to be false, if what Grell and Abramovitch say is true--helped to blind me. I was thrown off, too, by the finger-prints on the blotting-pad, which corresponded to those on the dagger, and also to those on the typewritten warning which Ivan sent me. The only plausible motive for Grell's actions, if he was not guilty himself--and that we are fairly certain of--was his desire to shield some one else. There could be only one person for whom he was willing to make such a sacrifice--Lady Eileen Meredith."

"Yes, I understand that. But the finger-prints on the warning?"

"They puzzled me for a while. But that was made clear when I talked to Ivan. He had typed it on the blank half-sheet of a letter given to him by Grell. That letter--it is only an a.s.sumption of mine--was one that had been written to Grell by Lady Eileen. That clears that point."

"Still, I don't see how you have anything against Lola more than you had before."

"There is this. The weak link in the chain of evidence against Lady Eileen Meredith was the lack of motive. That was why I did not have her arrested immediately I found that it was her finger-prints upon the dagger. The strongest point against the Princess is the motive. She was married to Goldenburg, but was not on the best of terms with him. She was bought by Grell to play the part of Delilah to the blackmailer. My theory is this--bear in mind that it is only a theory at the moment.

Grell, for some reason, left her alone with Goldenburg in his study.

There was a quarrel, and she stabbed him. It must have been all over in a few seconds, and there was no outcry. You will remember that the body was found on a couch in a recess, and you may have noted that curtains could be drawn across to shield it from the rest of the room. Petrovska may have drawn the curtains and slipped away before Grell returned. She is a woman of nerve and would at once set about manufacturing an alibi."

"All this is very ingenious, Foyle," remarked Thornton, "but I don't know that it sounds altogether convincing to me."

"It is pure surmise, Sir Hilary. Its chief merit is that it fits the facts. Of course, Lady Eileen may be the murderess after all. I am only working out an alternative. To carry it on a bit further. When Lady Eileen came, Ivan showed her up to the room. No one answered his knock.

She went in and shut the door after her. It is my idea that there was no one in there when she discovered the dead man. She was dumbfounded at first, and probably the body being in the shade did not permit her to see the face clearly. She placed her hand on the hilt of the dagger, intending to withdraw it, but could not bring herself to use the necessary force."

"Why didn't she call out?" demanded Thornton. "It seems to me----"

"There is no accounting for actions arising out of sudden emotions. Lady Eileen Meredith is as extraordinary a woman in her way as the Princess Petrovska in hers. She had found a man murdered in her lover's study--and she may have had a shrewd idea of the reason why she was summoned there. You follow me? Probably as she stood there, hesitating what to do, Grell returned. I think it likely that he stood by the door, took in the situation quietly, and stole away with the impression that she had killed Goldenburg. If she was bending over the dead man, that was what he might naturally think.

"It is likely that he would make up his mind in an instant. To him the fact that she had raised no outcry would be significant of her guilt.

She, let us suppose, stole away, having made no attempt to examine the body closely and not daring to summon any one, for fear that Grell should prove to be the murderer. He watched her go, already determined to destroy the scent by taking the blame on his own shoulders.

"By the time she reached her own home reflection had shown her that there was one possible chance that Grell might not be guilty. She rang up the St. Jermyn's Club and asked for him. Fairfield answered, declaring that his friend was in the club, but busy--too busy to talk to the girl he was to marry next day, mark you. It is idle to suppose that she did not appreciate the excuse as a flimsy one--one manufactured perhaps for the purpose of an alibi. She must have gone to bed filled with foreboding.

"All this is hypothesis. I am supposing that she never closely inspected the features of the dead man. The next morning she is informed that Grell was the victim. At once the lie that Fairfield told her a.s.sumed a new aspect. She denounced him as the murderer. She dared not say that she was the first to discover the body, for that would have meant revealing that she knew he was being blackmailed.

"Then the Princess Petrovska paid her a visit and told her that Grell was not dead but in hiding. There was nothing for it, in default of any explanation, but to revert to the thought that he was the murderer. She went to extreme lengths to help him--even to forgery. She believes him guilty still; he believes her guilty."

"But Petrovska?" objected Thornton.

"I was coming to that. She is a clever woman. When Grell got in touch with her the following day she may have had many reasons for a.s.sisting him. She most likely had a shrewd idea of the situation and resolved to profit by it to avert suspicion. While Grell was suspected she would be safe. But it may have occurred to her that if we laid our hands on him and he told us anything, we might get on her track. Suppose that to be so, it is not difficult to see why she should take a prominent part in a.s.sisting him. She would still have a certain amount of money, for he paid her to come to England, and she, as we know, would stand at nothing."

"It all sounds very interesting," commented the a.s.sistant Commissioner, "but it looks to me as though it may be a tough proposition to get evidence bearing it out."

Foyle pulled out his watch. "My idea may all tumble to pieces as soon as a test is applied. I can't pretend to be infallible. But we can try. I am going back to Scotland Yard now, sir. It is ten o'clock. I expect to be at it all night. Are you coming back?"

"No, I don't think I can be of any a.s.sistance to you. I shall be glad if your theory does come out all right this time. The alternative suspicions are horrible. Good night, Mr. Foyle."

CHAPTER LIII

With his mind revolving the strength and weakness of his theory, Heldon Foyle returned to Scotland Yard. He paused for a moment at the door of the night-inspector's room.

"Anything for me, Slack?" he asked. "Has Mr. Bolt come in? Ah, there you are, Bolt. Come down to my room." He led the way down the green corridor, the divisional inspector following.

"Well?" asked the superintendent sharply, as he seated himself in his office.

"I have seen the manager, a hall-porter and a chamber-maid at the Palatial, sir. They repeat what they said in their statements before.

The Princess left the hotel at about ten o'clock. No one can fix the time precisely, but it was certainly not before ten. She made up her mind very suddenly, the manager tells me."

Foyle was rummaging with some papers. "Thanks very much, Bolt. Stand by in case I want you. Tell Slack if he hears from Mr. Green to ask him to leave things and come up to me."

He concentrated himself on the neat bundle of doc.u.ments in front of him, and gave his mind with complete detachment to the study of several of them. The investigation had narrowed itself. Whoever was guilty was in his hands. The choice lay between Robert Grell, Lady Eileen Meredith, and the Princess Petrovska.

The reconstruction of the crime for the benefit of the a.s.sistant Commissioner, Foyle had purposely made provisional, but he was becoming more than ever convinced in his own mind that, in spite of appearances, Lola was the person at the bottom of the matter. She had left the Palatial about ten. If, he argued, she had left Grosvenor Gardens immediately after the murder it would have been possible for her to get to the Palatial by that time and to immediately make arrangements to leave. But for all that his intuition told him he was right, he could see no way of fixing the guilt on her.