"Your similes are unfortunate," she stammered, with dry lips. "I do not use knives. I leave that for others, the coroner's jury to the contrary."

"Do you think the coroner's jury influenced my judgment, sweetheart?

Shame--I have more faith than you. I know that you are innocent of Spencer's death."

"You have every reason to know that I am innocent." Kathleen was thoroughly roused. "It is not a question of faith on your part,"

significantly. "I see no use in these discussions. It is better that we do not meet. Again I ask you to go--forever."

Without replying he turned and paced the room rapidly, hands in pocket, head bent forward. Kathleen watched him with burning eyes and aching heart. To outward seeming he had the attributes which make for success.

What mad blood-lust had made him throw the world away?

"Suppose I accede to your unreasonable request, Kathleen," he said, stopping before her. "Will you do something for me?"

"Yes," huskily.

"Then get from your father the specifications and drawings of his latest invention for me."

As if she had not heard aright, Kathleen stared at him.

"Wh-what is it you ask?" she stammered.

"The plans of your father's _latest_ invention," patiently. "I do not mean the camera."

"Either you or I are mad," she looked at him dazedly. "Do you realize that my father would not give me those plans--that I should have to steal them."

"Expediency knows no law," he muttered, not meeting her eyes. "Call it borrowing." Kathleen shrank back appalled.

"Good God! That you should be so base!" she cried. "For more than forty-eight hours I have closed my eyes to reason; deluded myself that you acted from temporary mental aberration--that Sinclair Spencer's death was unpremeditated. My impulse was to help--to save. Ah, you wooed me well this winter." Her voice broke and she drew a long quivering breath.

"It is a pitiful thing to kill a woman's love. Some day, perhaps, I shall be grateful to you. Go!"

He flinched at the scorn in her voice, but stood his ground doggedly. "Not until I get the drawings and specifications of the invention," he answered.

The slamming of the front door caused Kathleen to look in that direction, and Henry's entrance the next instant stayed the words on her parted lips.

"A special delivery for you, Miss Kathleen," he said, "from the State Department."

Kathleen took the proffered envelope mechanically.

"Wait, Henry," steadying her voice. "When Captain Miller calls again, he is not to be admitted, under any pretense."

"Very good, Miss Kathleen," and concealing his curiosity, the chauffeur moved swiftly away.

There was a pause which Miller broke. "Read your letter," he said composedly. "I can wait."

Kathleen was on the point of collapse; desperately she clung to her remnant of composure. Hardly conscious of her action, she tore open the outer envelope, and read the brief statement that the letter inclosed had been sent to her, care of the Department of State. With some stirring of curiosity not unmixed with dread, she examined the contents of the second envelope. It read:

"United Service Club,

"London, England.

"MY DEAR MISS WHITNEY:

"I send the inclosed, forwarded to me by Major Seymour, who was until recently a prisoner in Germany. My nephew, John Hargraves, was killed in action.

"Very truly yours,

"Percival Hargraves."

John dead! Her loyal friend dead--and killed in action! Through a blur of tears Kathleen read the stained scrap of paper inclosed in the Englishman's note:

"DEAR KATHLEEN:

"I saw Karl in London at Victoria Station. I swear it was he--warn Uncle--Kathleen ... Kathleen...."

Shaken with grief Kathleen raised her head and looked at her companion sitting immovable in his chair. If he felt any interest in the letter and her emotion, he did not evince it. Three years before, he, she, and John Hargraves had been friends in Germany. John, the soul of honor, loyal and unselfish in his friendship, had laid down his young life for his country. His last dying word had been of her--to warn her....

Kathleen stood erect, wrath drying the tears which affection had brought. John had seen Karl in London in war times; there was but one answer to the puzzle.

"Captain Karl von Mueller," she said cuttingly, "to use the name by which I knew you abroad, do you wish my father's invention for Germany?"

"I do." Rising quietly, he faced her, stern and unyielding. "Why dissemble any longer? Your father promised to sell it to us; then went back on his given word. In handing me the invention you will but redeem his pledge."

"You have a strange conception of honor." Her eyes were blazing with fury. "Your statement about my father is open to doubt. Captain von Mueller, I give you forty-eight hours to leave this country before I denounce you as a German spy."

"Really?" His slow smile of unbelief caused her to writhe inwardly. "Do you think the unsupported statement of a woman suspected of murder will find credence?" Kathleen clenched John Hargraves' letter until her knuckles shone white under the taut skin. "Secondly," he continued in the same quiet tone, "you speak tonight only of this winter. Have you forgotten our relationship in Germany?"

"That is hardly the term for it," she said proudly. "I met you at the house of a German schoolmate ..."

"And our friendship rapidly ripened into love," he said softly, never removing his gaze from her bloodless face. "Our walks in the meadows about Berlin, our elopement ..."

"But not our marriage," she burst in. "John Hargraves can testify that I left you."

"John Hargraves is dead."

"True," she could hardly articulate. "But we were not married."

"Quite so; that is my point--_I_ did not _marry_ you."

Kathleen swayed upon her feet and threw out her hand blindly for support.

"You cur! you despicable cur!" she gasped. "Don't touch me." But though she shrank from him, his strong hand steadied her toward the hall door.

"Washington society is surfeited with scandal," he said. "When more composed think of your father's latest invention."

If she heard him she gave no sign. Mental torture had exhausted her emotion. She never raised her head as he guided her to the staircase; her eyes stared only at his open right hand.

The house was dark except for the hall light burning dimly, when Winslow Whitney inserted his latchkey and entered the front door. Removing hat and overcoat, he made his way noiselessly to his studio in the attic.

With cautious movement he fingered the locks on his door. Would Miller's plan for catching Spencer's murderer work out? According to their arrangement he had left the door insecurely fastened.

Just as he was about to creep into the room, he heard distinctly in the stillness a whispered word in a voice his keen ear instantly recognized.

All idea of caution forgotten, he threw open the door and switched on the electric light. To outward appearances the room was empty.