"Don't forget that you have a lecture engagement this afternoon," she admonished as she pa.s.sed the cup across the table.

Mr. Hardwick nodded and sipped. "It is a most extraordinary case. The murder of that poor woman--a.s.suming that it was a case of murder--seemed wholly unprovoked. I gathered from the conversation among the officers that no motive was in evidence. It looks like a wanton, despicable crime."

Helen crumbled a piece of toast. "Professor Warburton is coming to see you at three this afternoon."

"I have a memorandum of the appointment on my desk." Mr. Hardwick smiled faintly. "Our minds seem to be pulling in opposite directions this morning. This Mr. Shei interests me. He appears to be a remarkable criminal. His audacity and the originality of his methods are unparalleled. I don't know that I ever encountered anything quite so mystifying as the circ.u.mstances surrounding the murder last night.

How the murderer went in and out without being seen is beyond understanding, and the subsequent removal of the body was the most amazing part of it all. There seems to be neither method nor reason in that. One thing appears certain. Mr. Shei could not have accomplished what he did unless he had been aided by accomplices. What do you think, my dear?"

Helen's head was lowered over her coffee cup. The captive sunlight in her hair gleamed and flashed.

"Your extra pair of gla.s.ses are at the optician's," she reminded him.

"Don't forget to stop for it."

Mr. Hardwick looked at her helplessly; then carefully, and from force of habit, he folded his napkin.

"I wonder whether the police will ever learn Mr. Shei's ident.i.ty," he murmured musingly. "So far the scoundrel has contrived to mystify them completely, but some day his egotism and love of self-glorification are apt to cause his undoing. In the meantime, however, he is likely to do a great deal of mischief. The fellow's effrontery is colossal, and his fearlessness and brains render him most dangerous. In some respects he bears a very close resemblance to that other notorious rogue, now reported to be in retirement."

Helen drew a quick breath. She bent her head a little lower over her cup. Her right index finger traced a design on the tablecloth.

"Another cup of coffee, dad?" was her only reply.

Mr. Hardwick appeared not to have heard. "You know who I mean. The man they used to call The Gray Phantom. For several years he was regarded as one of the cleverest and most dangerous criminals the world has ever known."

Slowly Helen raised her head. Her eyes, as they met her father's, were steady and bright.

"That was because the world didn't understand him," she said with emphasis. "The Gray Phantom wasn't really a criminal. He was only a--a sort of human dynamo whose energy happened to be turned in the wrong direction."

"Isn't that a distinction without a difference? A Robin Hood is an enemy of society despite the glamour with which he surrounds himself.

However," and Mr. Hardwick's face softened quickly, "I am deeply in The Gray Phantom's debt. He saved your life twice, and but for him I would now be a lonely and heartbroken old man."

Helen nodded eagerly. "And the a.s.syrian collection, dad. You spent most of your life gathering it, and you were almost overcome with grief when it was stolen. The Gray Phantom risked his life and liberty in order to recover it and restore it to you. He wouldn't have done that if he had been just an ordinary criminal."

"True," admitted Mr. Hardwick. "I shall be under obligations to The Gray Phantom as long as I live. The man has a number of excellent qualities, whatever may be said of his past. On the whole, it is not surprising that you have taken an interest in him."

Helen's eyes were lowered again.

There was a mingling of tenderness and worry in Mr. Hardwick's face as he looked at her. "I know just how you feel," he said softly. "A man who is trying to live down a dark past always exerts a strong romantic appeal on a woman of your impressionable age. I don't know why it is, unless it pleases her to think he is doing it for her sake. It makes me think of your play, 'The Master of His Soul.' All last night, until the interruption came, I was wondering whether your _Marius_ was not The Gray Phantom."

Helen sat rigidly still for a moment. Then her lips began to twitch.

She flashed her father a smile.

"Sometimes, daddy dear, you show a wonderful understanding of things that have nothing to do with a.s.syriology."

"I was right, then." His face sobered. "I hope you realize that, despite The Gray Phantom's admirable qualities, there is a gulf between him and you. But you are just as level-headed as was your mother, and I have no fear that the impulses of your heart will get the better of your judgment. We were discussing Mr. Shei. There seems to be a striking similarity between his methods and those of The Gray Phantom, except that the latter was never known to stoop to murder."

He paused for a moment and studied her averted face. "You puzzled me last night, dear. You will admit that your conduct was--er, peculiar."

"It's getting late, dad," murmured Helen, a bit confusedly glancing at her wrist watch. "You should have been at your office half an hour ago. And this is the first time I've known you to take an interest in a murder case."

"Once during the evening you gripped my hand and tried to point out something to me," pursued Mr. Hardwick, heedless of her remark. "You spoke incoherently, and I had not the faintest idea what it was about.

Then, a minute or so before the tragedy, you left the box and hurried away. Still later, while the officer was questioning you, I felt you were concealing something."

Helen, her fingers tightening about a fork handle, shook her head. "I answered every question he put to me."

"I know, dear. Yet you withheld a secret of some kind from him."

"Not exactly. I--I merely refrained from telling him something that--that I might have told."

"Something you had heard or seen?"

She hesitated for an instant. "If I had told all I had seen and heard, I wouldn't have been telling half of what I knew."

Mr. Hardwick leaned back against the chair and pondered this cryptic statement. He seemed puzzled rather than hurt by his daughter's evasive answers. Suddenly she looked up, saw the troubled expression in his face, and impulsively pushed back her chair and ran up behind him.

"Please don't ask me any more questions, dad." She put her arms around his neck and tilted her face to his. "It is true I held something back, but at the time I didn't know why. I merely felt that it wouldn't do to tell. This morning, after lying awake most of the night, I knew I had done the right thing." She gave a little laugh.

"Isn't it just like a woman to act first and look into her reasons afterward?"

"I--well, I suppose so. And what were your reasons?"

"Would you be hurt if I told you I would rather not explain them just now?"

"No; I trust you. Experience has taught me that I can depend upon you in spite of your mysterious little ways and madcap pranks. There is one thing I wish you would tell me, though." He stopped, fumbling for words. "Was your reticence last night prompted by a wish to shield someone?"

"No," was her prompt reply, and her eyes gazed frankly into his. "What put such a thought into your head?"

"I scarcely know. You'll think I am an old fool, but it occurred to me that perhaps you had discovered something that led you to think that Mr. Shei and The Gray Phantom are identical."

"And you thought I was protecting The Gray Phantom? What an idea! But you were wrong, dad--absolutely wrong."

"Then I am glad." Mr. Hardwick rose and put his arm around her waist.

"My goodness! Almost ten o'clock, and I have been sitting here gossiping like an old woman. You have taken a load off my mind, dear child. I was really worried."

She laughed, whisked a few crumbs from his coat, straightened his tie, and kissed him.

"And I hope," added Mr. Hardwick banteringly, "that Ura.n.u.s won't lead you into any more foolhardy adventures."

Again she laughed, but her face sobered the moment he turned away and left the room. A wiser, maturer expression settled over the wide-set eyes and the vivid lips. It seemed as though her talk with her father had left a disquieting impression in her mind. She moved absently about the room, setting things in order here and there, but the far-away gleam in her eyes told that her mind was scarcely aware of what her hands were doing. Presently she stopped before the open window and looked out. A building was going up across the street, and the groaning of derricks and screaming of steam whistles jarred discordantly in the back of her mind. Near the curb a group of laborers were mixing concrete, and a powdery substance was drifting in the air.

She came out of her abstraction with a little start. Her eyes were on the window sill, and she spelled out the characters she had written in the thin layer of dust.

"G-r-a-y P-h-a-n-t-o-m," she mumbled, puzzled and somewhat annoyed with herself. The faint pencilings in the dust seemed all the stranger because she had not been thinking of The Gray Phantom. Instead, her mind had been occupied by Mr. Shei and what the morning newspapers had said about the tragedy in the Thelma Theater. The accounts she had read had been largely speculation and conjecture. The dying woman's strange laughter and her mysterious allusion to Mr. Shei had afforded material for columns of vivid and imaginative description. The medical examiner had reluctantly admitted that Miss Darrow's death might have been caused by a poison administered hypodermically, but he had added that the symptoms were strange to him, and that he knew of no drug producing just such effects. A number of toxicologists had been interviewed, but they had declared that the few facts at hand were not sufficient to enable them to form an opinion, and the disappearance of the body rendered it doubtful whether the cause of death would ever be learned definitely.

Only one thing seemed beyond dispute and that was Mr. Shei's complicity in the affair. The elusive and highly accomplished rogue already had a score of astounding crimes to his record, and the Thelma murder was hedged with all the mystery and baffling detail with which he loved to mask his exploits. Miss Darrow's dying words were scarcely needed to turn the finger of suspicion in Mr. Shei's direction. The absence of clews, the uncertainty in regard to the motive, the audacity that marked the crime itself as well as the subsequent s.n.a.t.c.hing away of the body, all indicated a boldness and a finesse that left little doubt of Mr. Shei's guilt. Even if his own hand had not executed the crime, it seemed practically certain that his mind had planned and conceived it.

But who was Mr. Shei? The whole train of surmises and theories pivoted on that question. Not much was known of him save that he had a pa.s.sion for tantalizing the public and keeping the nerves of the men at headquarters on edge, and that his achievements had not been equaled in scope or brilliance of execution since The Gray Phantom's retirement. He took a diabolical delight in flaunting his name before the world while keeping his person carefully out of the reach of the law's long arm, and even the name was a challenge to the police and a teaser for the public imagination. Someone versed in dead languages had discovered that the word "shei" was the ancient equivalent of the modern _x_, the symbol of the unknown quant.i.ty, and it was generally agreed that the name fitted the elusive individual who bore it.

Yet the name meant nothing. It was only an abstraction, for it afforded no clew to its owner's ident.i.ty. The night before, while she sat beside her father in the Thelma Theater, a vagrant flash of intuition had come to Helen. She had seen the solution of the mystery in a swift, dazzling glimpse. The revelation had stunned and nearly blinded her, and thoughts had crowded upon her so thickly that she would have been quite unable to clothe them in words. The idea carried to her by that intuitive flash had seemed clear and unquestionable. It still seemed so, but her talk with her father had disturbed her a little and turned her thoughts in a new direction.

Again she looked down at the tracings in the dust. A smile, faint and wistful, reflected her softened mood, and a light of wonder and gentleness flooded her eyes. She reached out a hand to obliterate the telltale pencilings, but something restrained her. Besides, a freshly forming layer of dust was already blotting them out.