"Oh, from that point of view--" began the detective.

But Bruce was merely thinking aloud--rough-shaping his ideas as they grouped themselves in his brain.

"Perhaps I am wrong there too," he went on. "If this girl is working to instructions she would have refused to help me in any way, and she already knows that I am on the trail. There is one highly satisfactory feature in the Jane Harding adventure, Mr. White."

"And what is that?"

"The person, or persons, responsible for Lady d.y.k.e's death know that the matter has not been dropped. They are inclined to think that the circle is narrowing. In some of our casts, Mr. White, we must have come so unpleasantly close to them, that they deemed it advisable to throw us off the scent by a bold effort."

"No doubt you are right, sir, but I wish to goodness I knew when we were 'warm,' as I am becoming tired of the business. Every new development deepens the mystery."

The detective's face was as downcast as his words.

"Surely not! The more pieces of the puzzle we have to handle the less difficult should be the final task of putting them together."

"Not when every piece is a fresh puzzle in itself."

"Why, what has disconcerted you to-day?"

"Mrs. Hillmer."

"What of her?"

"I have had another talk with the maid,--her companion, you know,--a girl named Dobson. It struck me that it was advisable to know more about Mrs. Hillmer than we do at present."

Bruce made no comment, but he could not help reflecting that Corbett, the stranger from Wyoming, had entertained the same view.

"Well," continued the detective, "I went about the affair as quietly as possible, but the maid, though willing, could not tell me much. Mrs.

Hillmer, she thinks, married very young, and was badly treated by her husband. Finally, there was a rumpus, and she went on the stage, while Hillmer drank himself to death. He died a year ago, and they had been separated nearly five years. He was fairly well-to-do, but he squandered all his money in dissipation and never gave her a cent. Three years last Michaelmas she set up her present establishment at Raleigh Mansions, and there she has been ever since."

"Then where does the money come from? It must cost her at least 2,000 a year to live."

"That's just what the maid can't tell me. Her mistress led a very secluded life, and was never what you could call fast, though a very pretty woman. During this time she had only one visitor--a gentleman."

"Ah!"

"It sounds promising, but it ends in smoke, so far as I can see."

"Why?"

"This gentleman was a Colonel Montgomery--an old friend--though he wasn't much turned thirty, the maid says. He interested himself a lot in Mrs. Hillmer's affairs, looked after some investments for her, and was on very good terms with her, and n.o.body could whisper a word against the character of either of them. He was never there except in the afternoon.

On very rare occasions he took Mrs. Hillmer, whose maid always accompanied them, to Epping Forest, or up the river, or on some such journey."

"Go on!"

"I'm sorry, sir, but the chase is over. He's dead."

"Dead?"

"Yes. The maid doesn't know how, or when, exactly, but one day she found her mistress crying, and when she asked her what was the matter, Mrs.

Hillmer said, 'I've lost my friend.' The maid said, 'Surely not Colonel Montgomery, madam?' and she replied, 'Yes.' She quite took on about it."

"Had the maid no idea as to the date of this interesting occurrence?"

"Only a vague one. Sometime in the autumn or before Christmas. By Jove, yes; it escaped me at the time, but she said that soon after the Colonel's death another gentleman called and took her mistress out to dinner. I was so busy thinking about the colonel that I slipped the significance of that statement. It must have been you, Mr. Bruce."

"So it seems."

The barrister's active brain was already a.s.similating this new information. If a woman like Mrs. Hillmer had lost a dear and valuable friend--one who practically formed the horizon of her life--she would certainly have worn mourning for him. It was a singular coincidence that Mrs. Hillmer "lost" Colonel Montgomery about the same time that Lady d.y.k.e disappeared. Detective and maid alike had drawn a false inference from Mrs. Hillmer's words.

"We must find Colonel Montgomery," he said, after a slight pause.

"Find him!"

"Yes."

"I hope neither of us is going his way for some time to come, Mr.

Bruce," laughed the policeman.

"White, I shall never cure you from jumping at conclusions. Upon your present evidence Colonel Montgomery is no more dead than you are."

"But the maid said--"

"I don't care if fifty maids said. There are many more ways of 'losing'

a friend than by death. Pa.s.s me the Army List, on that bookshelf behind you there."

A brief reference to the index, and Bruce said:

"I thought so. There is no _Colonel_ Montgomery. There are several captains and lieutenants, and a Major-General who has commanded a small island in the Pacific for the last five years, but not a single colonel.

White, you have blundered into eminence in your profession."

"I'm glad to hear it, even as you put it, Mr. Bruce. But I don't see--"

"I know you don't. If you did, a popular novelist would write your life and style you the English Lecocq. Mrs. Hillmer 'lost' the gallant colonel at the same time that the world 'lost' Lady d.y.k.e. Find the first, and I am much mistaken if we do not learn all about the second."

"Now I wonder if you are right."

The detective's eyes sparkled with animation. It was the first real clue he had hit upon, and Bruce's method of complimenting him on the fact did not disconcert him.

"Of course I am right. You have done so well with the maid that I leave her in your hands. Try the coachman and the cook. But keep me informed of your progress."

White rushed off elated. So persistent was he in striving to elucidate this new problem that he paid no heed during some days to the side-light furnished by Jane Harding and her exceedingly curious powers as a letter-writer.

Bruce purposely left the inquiry to the policeman.

He realized intuitively that the disappearance of Lady d.y.k.e would soon be explained, but he shrank from subjecting Mrs. Hillmer to further questioning.

His abstinence was rewarded later in the week, for Mensmore came to see him. The young man wore an expression of settled melancholy which surprised the barrister greatly.