"Damn!" he cried as he received negative answers. "The current wasn't strong enough. It's going to get away."
Carnes jerked his automatic from under his armpit and poured a stream of bullets into the fleeing monster. Slower and slower the motion of the creature became, and its movements again became jerky and convulsive.
"Keep it in sight!" cried the doctor. "We may get it yet!"
Cautiously the three men followed the retreating horror, Leffingwell pushing before him the platform holding the ultra-violet ray apparatus. The chase led them over familiar ground.
"There is the crack!" cried the lieutenant.
"Too late!" replied the doctor.
He rushed forward and seized the lower limb of the monster and tried with all his strength to arrest its flight, but despite all that he could do it slid sideways through the crack in the wall and disappeared. A final backward kick of its leg threw the doctor twenty feet against the far wall of the cave.
"Are you hurt, Doctor?" cried Carnes.
"No, I'm all right. Put on your masks and start the gas! Quick! That may stop it before it gets in far!"