It is permissible in certain circumstances for the police to detain a suspect, without making any charge, for a period of not more than twenty-four hours. Heldon Foyle had taken advantage of this to hold Grell while he tried to draw further together the tangled threads of the investigation.

He had changed out of his tweeds and, once more the spick-and-span man about town, he sat down in his office with an order that he was to be informed the moment that Sir Hilary Thornton returned. Meanwhile, he occupied himself with a work of composition. It was necessary to break gently to the public the fact that Robert Grell was not dead. But it had to be done in the right way. He could not altogether see what evidence might have to be offered at the inquest, but he was sure the newspapers would label it "sensational." He wanted to prepare, at any rate, for the revelation of the dead man's identity. That there was no possibility of avoiding, but it could be rendered less startling if it did not come suddenly. And beyond the public interest in the case Foyle had another reason for the publication of his effort. He worked steadily and made three drafts before he had completed his task. Two of them he tore up, and the third he read over carefully, making one or two alterations.

"When the inquest in reference to the Grosvenor Gardens murder is resumed it is understood that evidence of a remarkable nature will be brought forward by the police. Inquiries made by the C.I.D. have placed it beyond all doubt that the crime was not a planned one, and evidence is still being collected against a suspected person.

"A man for whom a rigorous search has been made by the police has been found in a Sussex village by Scotland Yard officers, acting in conjunction with the county constabulary. He was taken to Malchester Row police station, where he has been detained. It is understood that he refuses to give any account of the circumstances in which he took to flight.

"On inquiry at Scotland Yard yesterday, a representative of this journal was informed that the officers engaged on the case expect to be in a position to clear up the mystery in the course of the next few days."

"That ought to do," he muttered as he blew down a speaking-tube. To the detective-inspector who came in response to his summons he handed the paper. "Have fifty copies of that made, and bring me one. Put some one to 'phone through to all the journalists on the list, asking 'em to call here at half-past six to-night. They're each to have a copy of that."

There was guile in Foyle's fixing of the time. He knew that the paragraph would be a bombshell in Fleet Street, and did not want it to explode prematurely. At half-past six all the evening papers would have ceased publication for the day. At half-past six, too, he would take good care to be far away from the hordes of Press men, hungry for details, who would strive to find more information from the hints given. At that time they were likely to find any person wiser than themselves, and he had seen to it that there should be no indiscretion at Malchester Row.

"Sir Hilary just come in, sir," said some one, opening the door just wide enough to permit a head to be thrust within; but before Foyle could move the Assistant Commissioner himself walked in.

"One moment, Sir Hilary," said the superintendent, and dashed out, to return again almost immediately. "I just wanted to make certain that we shouldn't be disturbed. There's a lot to tell you. Things have been happening."

"So I gather," said the other, settling himself in the arm-chair. "You've got Grell, I hear. What's the next move? Do his finger-prints agree?"

"They do not. He is not the murderer, but he won't say who is. The next move is, that I intend that to go in all the morning papers."

He placed in Thornton's hand a copy of the typewritten paragraph, and the Assistant Commissioner read it slowly through. "I don't quite follow," he said as he handed it back. "It hints that Grell will be charged with the murder."

"Exactly. It is intended to convey that impression. To tell you the truth, I have a piece of evidence of which I have not spoken to you before. It indicates a person possibly guilty whom we must not neglect. If she is guilty—which I half doubt—that paragraph may help us to get at the missing evidence."

His voice sank to a whisper and he leaned forward with arms outspread over his desk. As he spoke, Thornton's voice changed. He leapt to his feet and brought his fist down vehemently on the desk.

"I don't believe it, man!" he cried. "I don't believe it! It's incredible. You've made a mistake. It can't be. Why, you've believed it was Grell yourself all along. If you've made a mistake, then why not now?"

Foyle's chin became a trifle aggressive. Thornton's astonishment was natural, but the superintendent did not like the appearance of lack of confidence. His blue eyes were alight. "You can draw your own inference from the facts, Sir Hilary," he said coldly. "I am clear in my mind. I have done nothing, because I want to make the evidence as to motive indisputable. Should I find I am wrong I shall, of course, write out my resignation."

Thornton was not usually an impulsive man. He had recovered himself immediately upon his outburst and was once more calm and self-possessed.

"Don't be offended, Foyle," he said, more mildly. "I beg your pardon. It was just a bit startling at first. We've been associated too long for misunderstanding. I'll back you up, and there's not going to be any talk of resignations."

"Thank you, Sir Hilary," said the superintendent, entirely mollified. Going to the big safe he unlocked it and took something from the shelf which he handed to the Assistant Commissioner. The two bent over it.

It was nearly two hours before the two concluded their task. Sir Hilary, his hands clasped behind his back, walked in deep thought back to his own room. Heldon Foyle put on his hat and coat and ordered a taxi.

"Brixton Prison," he said to the driver.