CHAPTER I.

A MYSTERIOUS AFFAIR.

“A man and a woman together; then a man alone.”

Nick Carter thought this remark rather than uttered it in words, as he came to an abrupt pause in his walk and looked down upon the tracks in the snow.

There were no other tracks than those anywhere visible, save only his own, which he had made in his approach to the spot, and he was careful not to approach too near while he made the examination which only his curiosity suggested—for there could have been no other reason at the moment than curiosity to attract him.

But before him was a huge iron gate between two enormous posts; a gate which had the outward appearance of not having been opened in a long time, and, indeed, upon it now, as the detective looked at it, there was a formidable padlock, with its heavy chain, to hold the great barrier against all comers.

Nick Carter could see from where he stood that the lock was securely locked, that the chain had been drawn tightly around the spindles of the iron gate, and, therefore, that the man who had come out of the place alone, after having passed inside with the woman not very long before, had locked it.

There were the tracks he had made when he had turned about to fasten the gate when he came out alone, and there were his tracks when he walked away from the place.

But where was the woman? and why had she not come again with the man?

These were perfectly natural questions which the detective asked himself; natural, because he knew something about the grounds upon which those gates opened, and also something about the house within those grounds.

Still more, he knew something about the people to whom the magnificent residence and grounds belonged.

He remembered also that the light flurry of “sugar” snow which now covered the ground like a white sheet of tissue paper—and it was scarcely thicker than that—had fallen within the last hour.

So it followed that those tracks must have been made within that hour.

Within an hour a man and a woman had entered the grounds of Pleasantglades—for that is the name by which the magnificent estate was known, or, at least, it is the one that we will use here to represent it—within an hour the two had entered together, and the man had come out alone, locking the gate after him, and, therefore, leaving her there.

And Nick Carter knew that the great house was unoccupied; that there was not even a caretaker there, so——

Why had two gone in and only one come out?

Curiosity gave place to interest; and as he studied the footprints with still more care, interest became absorbtion.

Both persons had been well shod. The woman daintily so, for, as the detective looked even more closely, he came almost to the opinion that she had been wearing slippers.

And the tracks of the man suggested dress shoes, even pumps, if one was to call upon one’s imagination just a trifle.

The hour, be it said, when the detective discovered the tracks in the snow, was between two and three o’clock in the morning, and a hundred feet away from the gate an arc light glowed brightly. Otherwise, the place would have been intensely dark, for, although that flurry of snow had lasted but a few minutes, it was still cloudy and threatening.

If Nick had approached the gate from the opposite direction, he might not have noticed the tracks at all; but, as it happened, he had approached toward the light, and had looked directly down upon them, plainly revealed.

The place was quite near to New York; near enough so that the detective had gone there in his car since dark that night.

The business that had taken him there had nothing to do with this thing that now intere