Clinging together, the two walked with some caution, and it was well they did so, for the floor of the cave was suddenly interrupted by a chasm, which seemed to have rent the earth in two, and was so deep that they could not see to the bottom. It was spanned by a plank, green with slime and rotten with age, placed there perhaps by the smugglers as a means of retreating to a more secure hiding-place.