Leaving the War Department, Detective Mitchell debated for a second whether to walk around the back of the White House grounds to the Municipal Building, or to go to Pennsylvania Avenue and take an east bound electric car. But there was no sign of let-up in the pelting rain, and pulling his coat collar up about his ears, he hastened toward the avenue, and at sight of an approaching car broke into a run. The usually empty sidewalks were filled with hurrying government employees, anxious to get their luncheon and return in the prescribed half-hour to the State, War, and Navy Departments, and the detective had some difficulty in dodging the pedestrians.

Seeing an opening among the lowered umbrellas, he stepped off the curb and dashed for the street car. He was almost by its side when the hoarse sound of a motor siren smote his ear, and glancing sideways, he saw a touring car bearing down upon him at full speed. In trying to spring backward his foot slipped on the wet asphalt and he sprawled forward on his knees. The automobile was almost upon him when strong hands jerked him safely to one side. Scrambling to his feet, Mitchell turned to look at the man whose strength and quickness had saved him from a nasty accident.

"Much obliged, Captain Miller," he said. "I owe you a great deal."

Miller stooped over and picked up the detective's hat. "Why don't you chaps arrest such speeders?" he inquired, pointing to the vanishing car.

"We do in most cases," returned Mitchell, brushing the mud from his trousers, and limping back to the sidewalk. "However, the driver of that car is exempt."

"Why?"

"We can't arrest a United States Senator."

"Ah, then you got his number." Miller led the way to the sidewalk.

"That car doesn't need a number to identify it," grumbled Mitchell. "Its color and shape are too distinctive. We on the force call it the 'Yellow Streak.' The car belongs to Senator Randall Foster; when he's at the wheel, the Lord help the pedestrians!"

"So it would seem," dryly. "Where are you going, Mitchell?" observing the detective's rather shaken appearance.

"To the Municipal Building."

"Suppose you come and lunch with me first at the Occidental," and the smile which accompanied the invitation was very persuasive. "It's near where you are going."

Mitchell had not lunched, and a hurried breakfast had been consumed before six o'clock. It was his hunger which had occasioned his haste to reach the Municipal Building and later a near-by cafÉ. His official business was not very pressing, and since meeting Miller at the Whitneys' two days before, he had heard of his attentions to Kathleen Whitney. The rumor had interested him as much as Miller's personality. Promptly he accepted Miller's invitation, and the two men boarded the next downtown car.

Within a short time they were both eating an appetizing lunch in the attractive restaurant of the Occidental. Just before the arrival of coffee and cheese, Mitchell sat back in his chair with a sigh of physical content. The Martini had warmed his chilled body, and the lassitude which comes after a hearty meal was stealing over him. Miller had proved an agreeable companion, able to talk upon any subject—except one, in spite of the detective's hints in its direction. Their table was in one corner apart from the others, and there was no danger of their conversation being overheard. Taking in their isolated position at a glance, the detective changed his tactics.

"I saw you at the Spencer inquest," he said abruptly, applying a match to his cigar. "What do you think of the verdict?"

"What every sane man thinks," answered Miller. "That the prosecution will have to secure more material and tangible proof before it can secure an indictment by the Grand Jury."

"I'm not so certain of that," responded the detective, ruffled by Miller's casual manner. "Our evidence against Miss Whitney was pretty conclusive."

"It would have been just as conclusive if applied to any other inhabitant of the Whitney house that night."

"Hardly." Mitchell smiled broadly. "I fear your friendship blinds you to the danger in which Miss Whitney stands."

Miller refrained from answering until their waiter had served the coffee and cheese and departed. "Circumstantial evidence will not always convict—fortunately," he said, helping himself to the Camembert. "What have you proved…."

"That Spencer was Miss Whitney's rejected lover," broke in Mitchell. "That the knife belonged to her; that she tried to remove incriminating blood stains on his shirt with her perfumed handkerchief; and that he held in his hand a flower, possibly broken from the bouquet which she was wearing at the time."

"It sounds formidable," commented Miller quietly. "But there are a number
of flaws. You have not absolutely proved that the knife belonged to
Miss Whitney, only proved that it is probable she might have owned it.
Wait"—as Miller started to interrupt. "The deputy coroner testified that
Spencer was killed by cyanide of potassium."

"Which, as Spencer did not swallow it, was administered by aid of the knife," retorted Mitchell hastily.

"The deputy coroner said he found no trace of the poison on the knife blade." Miller paused to refill Mitchell's coffee cup. "Secondly, cyanide of potassium is not a drug which Miss Whitney would be apt to have around."

"I saw a half-filled bottle of it in Whitney's work-shop last Wednesday."

"Quite true, I saw it there myself," admitted Miller. "I also saw that
Whitney kept his studio workshop under lock and key."

"To outsiders; but it is just possible he is not so strict about the members of his household, his testimony to the contrary," argued Mitchell. "The point is not well taken, Captain, and even if it were," he stirred his coffee thoughtfully, "Miss Whitney did not need to enter her father's workshop to secure the cyanide of potassium; I find she buys all his photographic supplies at a shop not far from here, and recently purchased a new supply of cyanide."

"Purely circumstantial evidence," responded Miller, keeping his expression unaltered by an effort. The detective's last statement had startled him. "In regard to the flower which Spencer held in his hand: you say it was probably broken from the bouquet which she wore at the time of committing the crime—I am, for the sake of argument only, admitting that she might be guilty. The medical evidence went to prove that Spencer was killed between three and four in the morning; it is straining probabilities to claim that a young girl, in donning her wrapper, pinned on a bouquet of flowers."

"How do you know she was not fully dressed? It was not so late in the morning; she could have gone to bed after the crime, or she may not have gone to bed at all."

"All supposition," scoffed Miller.

"Not quite all." The detective, nettled by his jeering smile, spoke hastily. "On further inquiry I learned from one of the servants today that Miss Whitney had on the same dress Wednesday morning, when her screams aroused the household, which she wore at dinner the night before."

"Ah, indeed?" Miller's smile had ceased to be skeptical, it was strained.
"And which servant imparted that information to you?"

"Henry, the chauffeur."

"For a chauffeur, Henry seems to know a great deal about what transpires
inside the Whitney house," observed Miller thoughtfully. "Tell me,
Mitchell, what motive do you attribute to Miss Whitney for the killing of
Sinclair Spencer?"

Mitchell looked uncomfortable, and it was not until Miller repeated his question that he spoke. "I believe Spencer persuaded Miss Whitney to meet him clandestinely that night, and threatened to compromise her if she refused again to marry him."

"Oh, come!" Miller spoke more roughly than he realized. "Wake up, Mitchell; you've been reading penny dreadfuls. Try and think up a motive which will hold water."

The detective flushed. "That is quite motive enough," he said. "If Miss Whitney takes the stand in her own defense she can, on that motive, enter a plea of killing to protect her honor…."

"And any jury in the country would acquit her," broke in Miller. "She would…."

"Thus escape the gallows," finished the detective.

"But I can suggest an even better solution of the problem," put in Miller suavely, although his fingers itched to choke his companion.

"And that is—?"

"That the detective force find the guilty party."

Mitchell suppressed a smile. "And where would you suggest that we hunt for this guilty party?" he asked. "Provided he or she is still at large, and not out on bail under indictment."

"Search among the men and women who spent Wednesday night at the
Whitneys', servants as well as guests."

"Captain," in his earnestness Mitchell leaned across the table, "it is contrary to all records of crime that a man or woman will commit murder without motive…."

"You forget homicidal maniacs."

"True, but they do not belong in this category," protested Mitchell. "No person in that house, except Miss Whitney, had a motive for killing Spencer."

"Motives are not always on the surface; I advise you to investigate …"

"Yes—?" eagerly.

"Is it true that arc lights have been installed at the United States navy yards and arsenals, which make them as light as day on the darkest night?"

"I believe so." Mitchell glanced perplexedly at his companion. Why was he changing the conversation?

"And that visitors are not encouraged to loiter on government reservations?"

"I believe such an order has been issued," conceded the detective.

"Also visitors are forbidden at the Government Radio Station at
Arlington?"

"Yes."

"And still there is a leak—government secrets are secrets no longer."

"How do you know that, Captain?" and the detective shot a look full of suspicion at him.

"I only know what Senator Foster has told me," carelessly. "I believe
Foster's advice has been sought in the matter."

"And why did he confide in you?"

"He desired my help," responded Miller. "Seemed to think my opinion might be worth something, but, honestly, Mitchell, I can't see anything to this secret leak business—the Secret Service operatives are putting a scare over on the government."

"It's more than that, sir. No more coffee," and the detective, his sudden doubts dispelled by Miller's sunny smile, leaned back once more in his chair. "It seems that officials here are awakening to the realization that government secrets are being betrayed. If the American troops are ordered to a certain point on the border, the order is known in Mexico before it is executed. It is the same with coded communications to Foreign Powers. The movements of our fleet are known to foreign naval attachÉs even before the maneuvers are carried out. The whereabouts of the smallest torpedo boat and submarine is no secret—to any but the American people."

"Is that so?" Miller looked politely incredulous. "And is the Secret
Service not investigating the matter?"

"Sure; they'll handle it all right." Mitchell twisted about in his chair. "At present, Captain, my entire attention is claimed by the Spencer murder. Where would you suggest that I begin my search among Whitney's household for a motive which will explain the murder?"

"Why not try and find Julie, the French maid?"

The eagerness died out of Mitchell's face. "We are trying," he said. "But we can convict Miss Whitney without her evidence."

"So you think Julie's testimony will implicate Miss Whitney still further in the crime?"

"I do. I have no doubt she is accessory after the fact, and, provided with funds by Miss Whitney, stole away so as not to give evidence against her."

"You have a curious conception of human nature, Mitchell," was Miller's only comment as he signed to their waiter to bring his check. He did not speak again until he and the detective were in the street. "You have overlooked a very important point, Mitchell, in your investigation of Spencer's murder."

"What is that?"

"You apparently believe that Miss Whitney murdered Spencer between three and four in the morning and then went back to her bedroom …"

"Go on," urged Mitchell.

"At the inquest all witnesses testified that Miss Whitney was the first to find Spencer and that she was in the elevator with him." Miller spoke with impressiveness. "Even the most hardened criminal would not have deliberately walked into that elevator and shut himself in with the man he had murdered a short time before—and yet, you argue that a highly strung, delicately nurtured girl did exactly that. It's preposterous!"

"It does sound cold-blooded," admitted the detective. "It is just possible that after committing the crime, she lost consciousness and remained in the elevator all night…."

"Talk sense!" ejaculated Miller disgustedly and, without waiting to hear the detective's thanks for his luncheon, turned on his heel and hurried up Fourteenth Street. Mitchell watched his tall, erect figure out of sight with absorbed attention.

"I'd give a lot to know who he suspects murdered Spencer," he muttered under his breath, and started for the Municipal Building.

As Miller approached his hotel, he thought he saw Foster's yellow touring car move away from the ladies' entrance. After procuring his mail he went at once to his room. He was about to open his letters when his eyes fell on an open drawer of his desk. Putting down the bundle in his hand, he carefully investigated every pigeonhole and drawer. The papers he looked for were missing.

Rising quickly, Miller examined the windows of his room and bathroom. They were securely fastened on the inside. In deep thought he went out into the hall to where the floor chambermaid and a companion were sitting in full view of his door.

"Have you been here long?" he asked.

"Yes, sir," replied the elder girl. "I've been on duty here ever since noon, and Mary," laying her hand on her companion, "was here all the morning."

"Has either of you seen anyone enter my bedroom?"

"No, sir, only yourself, sir," answered the first speaker, and Mary echoed her words.