Nothing for it but to keep moving down, so he does. His knife is out, and his senses are on alert. Sight is difficult, though, as the light tends to flash on just as his eyes are beginning to adjust. Then there's a hiss, the click of multiple sets of nails on metal, and Roland feels movement in front of him just in time to stab at it. Teeth click as it snaps at him and he turns his head, still trying to see. "Another one," he guesses, warning Susannah in case his guess is right.