Jon was slow in answering. "Yet, if we're going out at all...." He hesitated, then continued, "We'll either have to chase it away, or kill it." "If we can," his brother retorted. "I think our guns'll handle it," Jon said. "The question is, how are we going to do it without exposing ourselves?" Jak thought swiftly. "Maybe we could open the outer lock door a crack, just enough to see through and aim our guns." "Yes, I guess that's it." "Don't say anything to Mother," Jak cautioned. "Of course not, silly. Come on, let's see if we can kill it." The two ran to the airlock and opened the inner door. Leaving it open, they examined their guns to make sure they were fully loaded. Then Jon punched the button to open the outer lockdoor. It was possible to do this while the inner one was still open, since there was now air outside to equalize the pressure. When the door had swung open a couple of feet, Jon stopped the motor, and joined his brother, who was peering through the opening. The huge creature was still facing them, about forty yards from the ship. One of its rear feet was now pawing at the ground, tearing up great chunks of sod, while it roared its mighty challenge time and again. "I'll kneel and aim for the left eye. You stand over me and try to hit the other." Jak took swift command. "Then try for the brain or heart, and keep pumping while our ammo lasts or until we kill it." "Right." Jon took his place and aimed his gun. "Count three and we'll fire together." Jak knelt and steadied his rifle with one elbow on his extended knee. "One ... two ... three ... fire!" As the two shots crashed out the creature sprang into the air a couple of feet. A great scream of pain and rage shook the very ground and made the air tremble. It hesitated only a moment, then charged toward the ship at terrific speed. The boys pumped shots as fast as they could. Both had hit the head, but neither had put out an eye as they had hoped. They kept firing as fast as they could work their guns. Blood spouted from numerous wounds on the beast. But still it came on madly, with swift though lumbering bounds. "Back quick, and shut the door," Jak yelled as his hammer clicked on an empty gun. He pushed backward and scrambled to his feet as Jon leaped to the door controls. The heavy door swung shut ... and the boys breathed a sigh of relief. But almost at once their eyes filled with fear. They cringed back when they felt the ship itself shudder as that heavy body struck against it. As swiftly as their trembling legs would carry them, they raced back to the control room. They reached it just in time to see the huge triped lunge against the side of the ship a second time ... and again held their breaths as it did so once more.