"Carnes," he said at length, "do you see anything on this gun that looks like tooth marks?"
"Nothing, Doctor."
"Neither do I. There are some marks here which might quite conceivably be finger-prints of a forty-foot giant, and those two parallel grooves look like the result of severe squeezing, but there are no tooth marks. Strange. There is no persistent odor on the gun, which is also strange. Well, there's no use in theorizing: we are confronted by a condition and not a theory, as someone once said. Let's put on those baseball shoes and see what we can find out."
Dr. Bird led the way into the cave, Carnes and the lieutenant following closely with electric torches. In each hand Dr. Bird carried a phosphorus hand-grenade. No other weapons were visible, although the doctor knew that Carnes carried a caliber .45 automatic pistol strapped under his left armpit. As they passed into the cave the lieutenant stepped forward to lead the way.
"I'm going first," said the doctor. "Follow me and indicate the turns by pressure on my shoulder. Don't speak after we have started, and be ready for instant flight. Let's go."
Forward into the interior of the cave they made their way. The iron cleats of the baseball shoes rang on the floor and the noise echoed back and forth between the walls, dying out in little eerie whispers of sound that made Carnes' hair rise. Ever forward they pressed, the lieutenant guiding the doctor by silent pressure on his shoulder and Carnes following closely. For half a mile they went on until a restrainable pressure brought the doctor to a halt. The lieutenant pointed silently toward a crack in the wall before them. Carnes started forward to examine it, but a warning gesture from the doctor stopped him.
Slowly, an inch at a time, the doctor crept forward, hand-grenades in readiness. Presently he reached the crack and, shifting one of the grenades into his pocket, he drew forth an electric torch and sent a beam of light through the crack into the dark interior of the earth.
For a moment he stood thus, and then suddenly snapped off his torch and straightened up in an attitude of listening. The straining ears of Carnes and Lieutenant Pearce could hear a faint slithering noise coming toward them, not from the direction of the crack, but from the interior of the cave. Simultaneously a faint, musky, reptilian odor became apparent.
"Run!" shouted the doctor. "Run like hell! It's loose in the cave!"