"Have patience yet a little longer. Indeed, Mr. Lawrence, I feel deeply for your distress, and will do all I can to alleviate it," said the detective, in a tone of respectful sympathy.

"Thank you, Shelton. I believe that you will," said the banker, gratefully. "And now about this rascally physician. You were very clever in finding him out. How did you manage it?"

"It would weary you if I went into details, Mr. Lawrence. I arrived at my knowledge after much time and labor. But I will briefly explain that I furnished the old s.e.xton who helped on this trouble a deputy in his business, and disguising the old fellow thoroughly, I took him about with me night and day until he recognized his man and pointed him out to me."

"It seems incredible that a man with a good profession and of fair repute should be found engaging in such a nefarious scheme," said Mr.

Lawrence, in amazement.

Mr. Shelton smiled knowingly.

"My dear sir," he said, "there is nothing incredible, nor even uncommon about it. My experience in the detective line has made me familiar with a hundred such cases. Men steeped in every iniquity are found concealed under the guise of respectable professions or genteel business. Wolves in lamb's clothing, you know."

"It is shocking to think of," said the banker. "Well, can anything be done with this Pratt? Should not he be arrested at once on the charge of bribery?"

"And thereby lose the chance of tracking him to the hiding-place where he has the body concealed?" said Mr. Shelton. "Oh! no, Mr. Lawrence, we will not molest him yet. I have my eye upon him. Like Mr. Colville, he is a shadowed man; I have a colleague in this business, and we each have our marked man to watch. Dr. Pratt's profession takes him abroad so much and into so many houses that it will be difficult to track him, but depend upon it we shall run him to earth at last."

"I truly hope so; your recent discoveries have put new heart into me, Shelton; may G.o.d prosper you in your undertaking," said the banker, supplementing this aspiration with a very large roll of bank-bills which he slipped into the detective's hand.

"Thank you, sir," smiled Shelton. "That material way you have of supplementing a prayer is not a bad thought. I may count upon your silence about what I have disclosed--may I?"

Mr. Lawrence placed his fingers on his lips with a nod and smile.

"All right, I'll rely upon you," said the disguised detective, and with a brief "good-day, sir," he went buoyantly away on the secret mission that meant detection and ruin to Messrs. Pratt and Colville.

The banker returned to his counting-room with renewed hope and vigor.

The impenetrable darkness that had hovered over Lily's disappearance so long seemed to be lifting at last and a gleam of light shone through the little rift in the clouds.

CHAPTER XXII.

Mr. Shelton spoke truly when he said to Mr. Lawrence that he would shadow Harold Colville like a bloodhound.

By day and by night, on foot or on horseback, in various disguises, he kept himself on the track of the fine gentleman.

For several weeks he kept up this close espionage, but at the end of that time he seemed no nearer his object than when it was first begun.

Mr. Colville's comings and goings seemed to be quite the same with those of other gentlemen of his means and position.

He frequented theaters and gaming-houses; he was a welcome and much sought-for partner in ball-rooms, and was smiled upon by scheming mothers with marriageable daughters.

Thus far Mr. Shelton had seen nothing on which to seize as a possible clew to Mr. Colville's mysterious presence in Mr. Lawrence's house the night of Lily's appearance.

Mr. Shelton had made one discovery, however, though he did not begin to attach much importance to it. It was that Doctor Pratt and Harold Colville were acquainted with each other, and, moreover, that they sometimes "hunted in couples."

That is to say, the worthy physician occasionally stopped his carriage on meeting Colville, whereupon the latter would spring in and accompany the doctor on his round of visits, seeming deeply interested in the conversation they pursued together.

Mr. Shelton was puzzled to decide whether there was any collusion between the gay man of fashion and the busy physician, or whether it was only one of those odd friendships that are sometimes observed to exist between persons of totally different temperaments and pursuits.

Sometimes he was inclined to believe it was only the latter.

But he noticed a fact at last that struck him as rather peculiar.

Following the pair closely on his stout, black horse, he had seen that Colville always remained in the carriage while the physician went into the houses to pay his visits to the sick.

On this occasion, which struck him so forcibly, they drove quite out upon the outskirts of the city, and stopped before a house standing almost a half mile distant from any other.

This house, the detective observed, had a gloomy and forbidding aspect, being closely shuttered and surrounded by a very high stone wall.

Here Dr. Pratt descended and fastened his horse. Mr. Colville also sprang out, and they entered with a familiar air, the heavy gate closing and shutting them in.

"Now, that is rather strange," thought the detective as he walked his horse slowly past the deserted-looking place.

"What business has Colville in there? I can imagine that Pratt may have a patient inside those gloomy walls; but what the deuce can Colville have to do with it? I am almost positive that I heard shrieks issuing thence when they went in at the gate. I wonder can it be a private asylum for the insane?"

He spurred his horse ahead and rode on for some distance, then paused, and remained as erect and still as a statue while he watched and waited for the pair of confederates to come forth. But at least an hour elapsed before they emerged, and pursued the devious tenor of their guilty way.

"Now, upon my word," thought the wary spy, "Doctor Pratt must have a very interesting case inside of those gloomy, prison-like walls. I have a mind to stop somewhere in the neighborhood and inquire about the inhabitants thereof."

He accordingly suffered Doctor Pratt's carriage to drive on out of sight, and stopping before a cottage on the road with the ostensible purpose of obtaining a drink of water, he inquired of the woman who gave it to him as to the names of the people who inhabited the old house with the stone wall.

"And indade, it's mesilf that cannot tell ye, sor," said she, with a very broad Hibernian accent, "for shure, Mickey and mesilf have but lately moved intil the cot, and knows naught about the nayburs!"

Mr. Shelton rode on and made the same inquiry at the next house, but elicited no encouraging answer. People did not seem to know anything about the deserted-looking old house in such close proximity to them.

After several similar experiences he rode on quite disgusted with the general stupidity of the neighborhood.

Almost two miles from the old house that had so powerfully attracted his interest, he came upon a little house standing close to the roadside.

A kind-looking woman sat in the doorway, though the day was chilly, and as she kept knitting away on the homely gray stocking, sang cheerily at her work.

"Now that is a pleasant-looking old soul," he thought. "Perhaps her intellect is above the average of her neighbors. Perhaps she is better informed than they are. At any rate, I will speak to her."

He dismounted from his horse this time, fastened him at the gate-post, and walked up the narrow path to the door.

The good woman arose in quite a flutter.

"Do not let me disturb you," said he, courteously. "I only wish to trouble you for a drink of water. I have ridden far and feel very thirsty."

"Certainly, sir," said the woman, in a voice as pleasant as her face.

"Come in and have a seat, sir, and you shall have a draught fresh from the spring."

She hurried away on hospitable thoughts intent, and soon returned with a gla.s.s of pure cold water. The guest sat still in his homely chair and sipped at the water very slowly considering how thirsty he had professed himself to be.

The fact was, he had drank several gla.s.ses of water already while prosecuting his inquiries, and began to feel himself almost unequal to this latter one.

"You do well to sip your water slowly, sir," said the woman, observing him, "for the doctors do say that it is very imprudent to drink rapidly when tired and overheated."