"Never throw away a chance," thought Jonathan.

"Who knows but this key may open a golden lock one of these days ?" And, picking it up, he thrust it into his pocket.
Arrived beneath an aperture in the broken roof, he was preparing to pass through it, when he observed a little heap of tiles upon the floor, which appeared to have been recently dislodged.

"He _has_ passed this way," cried Jonathan, exultingly; "I have him safe enough." He then closed the lantern, mounted without much difficulty upon the roof, and proceeded cautiously along the tiles.
The night was now profoundly dark.

Jonathan had to feel his way.

A single false step might have precipitated him into the street; or, if he had trodden upon an unsound part of the roof, he must have fallen through it.