Both Sir Hilary Thornton and Chief Inspector Green were waiting for Heldon Foyle when he returned to his office. The superintendent darted a question at the chief inspector as he flung off his overcoat.

"Yes, sir," answered Green. "She's at Malchester Row now. There was no trouble at all. She came up to the Grange at half-past three, in a car, and asked the maid who answered the door for Mrs. Ellis. The girl showed her into a sitting-room, acting on my instructions, and I walked in on her and told her I should detain her. She was angry at first, but in a moment or two she laughed, and asked if Mr. Grell was taken. That was all there was to it. I brought her back straight away by train. She seemed to treat it as a joke, but never a word about the case did she utter."

"And how did you get on, Foyle?" demanded the Assistant Commissioner.

The superintendent plumped into a chair. "I am sending a man up to get a statement from Ivan," he said. "There's much to be said for that Russian if his story is true—and I couldn't see any holes in it."

He related particulars of the interview that had taken place in the cell. Neither Thornton nor Green spoke till he had finished. The Assistant Commissioner smoothed his moustache, Green rubbed his head.

"Then Grell admitted the murder to Ivan?" said the latter, turning a puzzled face to Foyle. "You told me he was not the murderer."

"Nor was he," answered the superintendent. "According to Ivan, there was no blood on his clothes or on his hands a few minutes after Goldenburg was killed."

"Well, this beats all," exclaimed Green. "I'm hanged if I understand!"

Foyle lowered his voice to a whisper, and Green's saturnine face became a study as he listened. He gave a little gasp. "It lies between the three of them," said Foyle. "I am inclined to believe that we have been rather wrong in our first impressions of the finger-prints. But it never does to take chances. Suppose you go and take charge at Berkeley Square. There are four men there already. Lady Eileen has certainly had something to do with this, and we don't want to lose sight of her."

Green went off, his lips puckered into a whistle. Thornton gave a shrug. "And now?" he said. "It seems to me rather a deadlock if Mr. Grell and the Princess remain obstinate."

"Yes," agreed Foyle. "It's one of those cases in which it is a pity we're not allowed to adopt the French method of confrontation. Still, there's a shot in the locker yet. Perhaps you might care to come along with me and see Grell now. These disclosures of Ivan's make a difference, and rather bear out a suspicion I've had since I talked with Grell."

The Assistant Commissioner agreed, and in a little they were walking to Malchester Row police station. The office of Bolt, the divisional detective-inspector, was empty, and with an order that they were not to be disturbed, Foyle and his chief entered the room. Under the escort of a uniformed inspector, Grell was brought in. The superintendent closed and locked the door, Grell moving stiffly aside to allow him to do so.

"Do you know Sir Hilary Thornton?" asked Foyle suavely.

Grell bowed. The Assistant Commissioner extended his hand. "How do you do, Mr. Grell? I should have been glad to have met you under happier circumstances, but I assure you that the respect in which I have always held you is not lessened by this unfortunate business."

The prisoner shook hands doubtfully and his eyes flashed a questioning look upon Foyle. The superintendent's face was blandly unconscious of the effect of the Assistant Commissioner's remark, although the words had been rehearsed and revised a dozen times during their walk to the police station. But he had to do with a man as astute and ready as himself.

"That's very good of you, I'm sure," said Grell, and a smile illumined his face as he added: "Though I don't know why this matter should increase your respect."

"Don't you?" said Foyle, laying stress on his words and eyeing the other meaningly. "Suppose it is because since I left you this morning, Ivan Abramovitch has made a full statement to me?"

A little apprehensive shudder swept through Grell's frame. His lips opened to say something, but he checked himself suddenly. "What's that to do with me?" he demanded quietly.

"A great deal, if it's true, as I know it to be. Now, Mr. Grell, you are not obliged to answer any questions unless you like—you know that—but I warn you that your failing to do so cannot prevent us arresting the guilty person. We know you are innocent—though whether you may be charged as an accessory after the fact or not is another question. What do you say?"

The prisoner had leaned his arm on the table. His fists were clenched until the finger-nails bit into the flesh.

"If you've made up your minds, so much the better for me," he said with a half laugh. "Who have you fixed your suspicions on?"

It was clear that he had doggedly set himself to avoid affording them any help. His chin was as fixed as that of Foyle himself. The strong wills of the two men had crossed. The superintendent felt all his fighting qualities rise. He was determined to break down the other's wall of imperturbability. He accepted Grell's silence as a challenge.

Thornton's gentle, cultured voice broke in. "We are only anxious to spare you as much as possible. You are a prominent man, and though you must be brought in, it will serve no purpose to increase what will create enough scandal."

"I fear you are wasting your time, gentlemen," said Grell, stretching himself wearily. "Won't it cut this short if I admit that I killed Goldenburg? I will sign a confession if it will please you."

The eyes of Thornton and Foyle met for a second. There was a meaning look in the superintendent's, as who should say, "I told you so." Then he took from his breast-pocket a piece of paper, which he unfolded as he smiled amiably at Grell.

"That is childlike. Your finger-prints prove it is false. Perhaps you will tell us what underlies this note that you sent to Lady Eileen Meredith the day you left London."

He read:

"We are both in imminent danger unless I can procure sufficient money to help me evade the search that is being made for me. If I am arrested, I fear ultimately exposure must come. If you have no other way of obtaining money, will you try to get an open cheque from your father? You could cash it yourself for notes and gold and bring it to me. For God's sake do what you can. I am desperate."

He read it swiftly, as though certain of the accuracy of the words. As a matter of fact, he was not. He had pieced together the broken words and phrases that he had taken from the burning paper in Eileen Meredith's room as well as he could. In filling up some of the gaps he might have been preposterously wrong.

"Where did you get that?" demanded Grell. "Eileen told me she had burnt it."

His words were an admission that the note was practically correct. Foyle placed it carefully back in his pocket, while Grell stared at the opal shade of the electric light.

"She did burn it," he answered. "I chanced to be able to retrieve the message. I feel certain that, however dire your necessity, you would not have written to her in that strain unless you had some strong reason. Who did you mean when you said 'both in imminent danger'?"

"Ivan and myself, of course."

"Ivan was under arrest at that time. Nothing could avert the danger from him. And you say that you feared exposure if you were arrested. That, of course, meant that you would be unable to keep shielding the person you are shielding?"

A dangerous fury blazed in Grell's eyes—the fury of some splendid animal trapped and tormented yet unable to escape from its tormentors. He glared savagely at the superintendent.

"I am shielding no one," he declared.

"You can, of course, make any answer you like. Suppose we go on to another point which perhaps you will have no objection to clearing up now. We have Harry Goldenburg's record. We know he had been blackmailing you, and we know that he was your brother. No; sit still. He was your brother, was he not?"

"My half-brother. How did you know that? How did you know he was blackmailing me?" Grell spoke tensely.

"Oh, simply enough. The likeness was one thing, and a hint I got from Ivan that he was a relative confirmed me in an opinion I had already formed by another fact—which I observed when I saw you at Dalehurst—that you had a similar walk. You will remember, I asked you if he was a relative, but you would not answer. The supposition that you were being blackmailed was borne out by inquiries made for us by Pinkerton's, which proved that Goldenburg had visited you several times and that he was always in funds after he left you, however low he might be before. I think it is a fair inference."

"Quite fair." Grell's face was a little drawn, but he spoke quietly. "You are quite correct, Mr. Foyle. As you know so much, there can be little harm in enlightening you on that part of the story. I take it that you treat it as confidential."

"Unless it becomes necessary to use it for official purposes, as evidence or otherwise," said Thornton before the superintendent could reply. "We cannot give an absolute pledge."