Robert Grell lay sprawled awkwardly on the couch, his face turned towards the wall, one leg trailing on the floor. A dark crimson stain soiled the white surface of his shirt, and one side of his dinner jacket was wringing wet. The dagger still remained in the wound, and it was that riveted Foyle's attention. He stepped back quickly to one of the men at the door.

"Send Mr. Grant to me," he ordered.

Returning to the body, he gently withdrew the knife, handling it with the most delicate care. "I've never seen anything like this before," he said. "Queer thing, isn't it?"

It was a sheath knife with a blade of finely tempered steel about three inches long and as sharp as a razor. Its abnormality lay in a hilt of smooth white ivory set horizontally and not vertically to the blade, as is a rule with most knives.

Foyle carried it in the palm of his hand nearer to the light and squinted at it from various angles. One at least of the observers guessed his purpose. But the detective seemed dissatisfied.

"Can't see anything," he grumbled peevishly. "Ah, there you are, Grant.

I want to see whether we can make anything of this. Let me have a little graphite, will you?"

The finger-print expert took an envelope from his pocket and handed it to the superintendent. From it Foyle scattered fine black powder on the hilt. A little cry of satisfaction came from his lips as he blew the stuff away in a little dark cloud. Those in the room crowded around.

Outlined in black against the white surface of the ivory were four finger-prints. The two centre ones were sharp and distinct, the outside prints were fainter and more blurred.

"By Jove, that's good!" exclaimed the professor.

Foyle rubbed his chin and handed the weapon to Grant without replying.

"Get one of your men to photograph those and have them enlarged. At any rate, it's something to go on with. It would be as well to compare 'em with the records, though I doubt whether that will be of much use." He drew his watch from his pocket and glanced at it. "Now, if you will excuse me, gentlemen, I should like to have the room to myself for a little while. And, Grant, send Green and the photographer up, and tell Waverley to act with Bolt in examining the servants."

The room cleared. Harding lingered to exchange a few words with the superintendent.

"I can do nothing, Mr. Foyle," he said. "From a medical point of view it is all straightforward. There can be no question about the time and cause of death. Good night,--or rather, good morning."

"Thank you, Mr. Harding, good morning."

His eyes were roving restlessly about the room, and he dictated the work the photographer was to do with scrupulous care. Half a dozen times a dazzling flash of magnesium powder lit up the place. Photographs of the room in sections were being taken. Then with a curt order to the photographer to return immediately to Scotland Yard and develop his negatives, he drew up a chair to the couch and began to go methodically through the pockets of the dead man.

Green stood by, a note-book in hand. Now and again Foyle dictated swiftly. He was a man who knew the value of order and system. Every step in the investigation of a crime is reduced to writing, collected, indexed, and filed together, so that the whole history of a case is instantly available at any time. He was carrying out the regular routine.

Only two things of any consequence rewarded his search--one was a note from Sir Ralph Fairfield confirming an appointment with Grell to dine at the St. Jermyn's Club the previous evening; the other was a miniature set in diamonds of a girl, dark and black-haired, with an insolent piquant beauty.

"I've seen that face before somewhere," mused the superintendent.

"Green, there's a 'Who's Who' on the desk behind you. I want Sir Ralph Fairfield."

Rapidly he scanned the score of lines of small type devoted to the baronet. They told him little that he had not known before. Fairfield was in his forty-third year, was the ninth baronet, and had great estates in Hampshire and Scotland. He was a traveller and a student. His town address was given as the Albany.

"You'd better go round to Fairfield's place, Green. Tell him what's happened and bring him here at once."

As the chief inspector, a grim, silent man, left, Foyle turned again to his work. He began a careful search of the room, even rummaging among the litter in the waste-paper basket. But there was nothing else that might help to throw the faintest light on the tragedy.

A discreet knock on the door preceded Waverley's entrance with a report of the examination of every one in the house. He had gathered little beyond the fact that Grell, when not concerned in social duties, was a man of irregular comings and goings, and that Ivan, his personal valet, was a man he had brought from St. Petersburg, who spoke French but little English, and had consequently a.s.sociated little with the other servants.

Foyle subsided into his chair with his forehead puckered into a series of little wrinkles. He rested his chin on his hand and gazed into vacancy. There might be a hundred solutions to the riddle. Where was the motive? Was it blackmail? Was it revenge? Was it jealousy? Was it robbery? Was it a political crime? Was it the work of a madman? Who was the mysterious veiled woman? Was she a.s.sociated with the crime?

These and a hundred other questions beat insistently on his brain, and to none of them could he see the answer. He pictured the queer dagger, but flog his memory as he would he could not think where it might have been procured. In the morning he would set a score of men making inquiries at every place in London where such a thing was likely to have been obtained.

He was in the position of a man who might solve a puzzle by hard, painstaking experiment and inquiry, but rather hoped that some brilliant flash of inspiration or luck might give him the key that would fit it together at once. They rarely do come.

Once Lomont, Grell's secretary, knocked and entered with a question on his lips. Foyle waved him impatiently away.

"I will see you later on, Mr. Lomont. I am too busy to see you now. Mr.

Waverley or Mr. Bolt will see to you."

The man vanished, and a moment or two later a discreet tap at the door heralded the return of Green, accompanied by Sir Ralph Fairfield.

The baronet's hand was cold as it met that of Foyle, and his haggard face was averted as though to avoid the searching gaze of the detective.

CHAPTER IV

Fairfield, awakened from sleep by the news of the murder of his friend, had stared stupidly at the detective Foyle had sent to him.

"Grell killed!" he exclaimed, "Why, he was with me last night. It is incredible--awful. Of course, I'll come at once--though I don't see what use I can be. What time was he murdered?"

"About ten o'clock. So far as we know you were the last person to see him alive--except the murderer," said Green. "Believe me, we're sorry to have to trouble you."

The baronet's face had suddenly gone the colour of white paper. A sickening dread had suddenly swept over him. His hands trembled as he adjusted his overcoat. He remembered that he had a.s.sured Lady Eileen that Grell had been with him at the club from six till eleven. What complexion would that statement bear when it was exposed as a lie--in the light of the tragedy? His throat worked as he realised that he might even be suspected of the crime.

The ordinary person suddenly involved in the whirlpool of crime is always staggered. There is ever the feeling, conscious or unconscious: "Why out of so many millions of people should this happen to _me_?" So it was with Sir Ralph Fairfield. He pictured the agony in Eileen Meredith's eyes when she heard of the death of her lover, pictured her denunciation of his lie. The truth would only sound lame if he were to tell it. Who would believe it? Like a man stricken dumb he descended in the lift with Green, out into the wild night in a taxicab, his thoughts a chaos.

He was neither a coward nor a fool. He had known close acquaintance with sudden death before. But that was different. It had not happened so. He was incapable of connected thought. One thing only he was clear upon--he must see Eileen, tell her the truth and throw himself on her mercy.

Meanwhile he would answer no questions until he had considered the matter quietly.

This was his state of mind when he shook hands with Foyle. He had schooled his voice, and it was in a quiet tone that he spoke.

"It's a horrible thing, this," he said, twirling his hat between his long, nervous fingers.

Foyle was studying him closely. The movement of the hands was not lost upon him.

"Yes," he agreed, stroking his chin. "I asked you to come here because Mr. Grell dined with you last night. Do you know if he left you to keep an appointment?"

"No--that is, it might have been so. He left me, and I understood he would be back. He did not return."

"At what time?"

Fairfield hesitated a second before replying. Then, "I haven't the remotest idea."

The face of Foyle gave no indication of the surprise he felt. He did not press the question, but slid off to another.

"Do you know of any woman who was likely to visit him at that time of night?"

"Great heavens, no, man! Do you suspect a woman? He----" He checked himself, and looked curiously at the detective. "Mr. Grell was a friend of mine," he went on more quietly. "Things are bad enough as they are, but you know that he had influential friends both here and in America.

They won't thank you, Mr. Foyle, for trying to go into such things."