And his picklock, which he was never without, had not been intended for locks of that sort, for he found when he examined it that it was of the most complicated pattern of padlock, and that it had probably been made to order for the owners of the place.
Indeed, as he examined it more closely, he found it to be one of those rare locks which require the use of two, and sometimes three, keys, to open them.
His picklock was therefore out of business for once.
But he had his pocket case of delicate tools with him, and among those tools was a file which would eat through that chain, or any other one, in short order; and so, at last, he took it from the case and adjusted it.
It was the last extremity to which he resorted, for he disliked the idea of filing his way into the place, necessary as it seemed to be, that he should enter. He would greatly have preferred to scale the wall, or to pick the lock if either had been possible.
He did not like the idea of leaving the place unguarded even temporarily, when he came out again, for, after all, there was no certainty that he would find anything wrong, and it was quite possible that there might be a plausible and logical reason and explanation for all the things he had discovered that had interested him so greatly.
But he had decided that he would go inside, and, therefore, he went inside with no more delay than was absolutely necessary.
That little file of his, no larger than the blade of a penknife, and not much longer, ate through the chain cleanly and rapidly, and, although we have taken so much time and space to describe his discovery of the tracks in the snow and to explain his reasonings upon that discovery, it is doubtful if more than fifteen minutes had actually elapsed after he first saw the footprints, until he opened one of the gates, passed through, and closed the gate after him.
Then, having rearranged the chain again with great care so that it would not be noticed that it had been tampered with, he turned to follow the tracks in the snow, that led toward the great mansion.