And yet he had seen it all with his own eyes, so he had to assure himself; and the old louis d’or which he had picked up among the dust of hundreds of years was still in his pocket. He drew it out and looked at it, and the coin seemed, by its incontrovertible reality, to put more practical thoughts into his head. That underground passage must have an end, an opening; and that opening would probably be on this side of the river. Slowly, thoughtfully, he retraced his steps, until he was exactly opposite the perpendicular cliff on which the castle, its foundations deep in the solid rock, stood. The ground on which Rees was standing, on the opposite bank, was an open and very undulating meadow, under the numerous hillocks of which the imaginative could fancy the graves of the besieging Puritans to have been made. It was so open, indeed, so fully exposed, not only to passers by, but to occupants of the cattle lodge and of a couple of adjacent cottages, that Amos Goodhare, in his exhaustive scourings of the neighborhood, had never dared to carry on his researches there except at night. Now Rees, less cautious, found himself strolling very slowly along with eyes fixed intently on the thick grass, which, cropped close by cattle on the higher ground, grew thick and lush at the water’s edge. At last he sat down immediately opposite the window in the rock which gave light to the vaulted apartment in which his adventures had begun. His feet were only just above the sedge, and the grassy ground on which he was sitting was so soft from the heavy rains that he found a great slab of earth giving way under his weight, and sliding gently down with him towards the water. He scrambled up hastily, but in regaining his feet he caused the displaced earth to come down still faster, so that he fell down on his hands and knees and cut his left wrist against a stone. This stone proved to be the upper edge of a great slab of rock, which the freshly-moved turf had grown over and hidden. Rees drew a long breath. Was this the other entrance to the underground passage?