With tubes of death as whips, and with death for themselves set as the stake for which they gambled, they went about their attempt to drive the brainless monster before them through the solid wall of the dome building. And there followed what was probably the strangest animal act the universe has ever witnessed. * * * * * The first thing to do was to rout the enormous lizard out of the corner where sullen fear had sent it squatting. Dex contrived to do that by standing next to the wall at its side, and sending a searing ray that just touched the scaly, tremendously thick hide. The monster bellowed deafeningly, and, with a spot smoking on its flank, waddled sideways to the center of the field. Its head and swaying long neck faced the Earthmen and its back was against the wall of the dome building. To that extent, at least, they had the creature placed; but they soon found that the struggle had only just begun. Brand got far enough around to focus his tube on the tip of the huge tail, in an effort to swing the gigantic thing about. There was an unearthly shriek from the colossal beast, and a foot and a half of its tail disappeared. "Careful," called Dex, his jaw set and grim as the monster lashed out in its wrath. "If you bore in too long with that tube there'll be nothing left of our tank but a cloud of smoke." Brand nodded, wordlessly, walking on the balls of his feet like a boxer, holding himself ready to swerve the thing should it charge them. Which--next instant--it did! With a whistling bellow it gathered its tons of weight and thundered with incredible quickness at the gnats that were stinging its flanks and tail. Desperately Brand played the tube across the vast chest, scoring a smouldering gash in the scale-covered flesh just above the gash Dex had seared a few moments before. "Sorry, old fellow," Brand muttered to the screaming beast. "We hate to bait you like this, but it has to be done. Come on, now, through that wall behind you, and give us a chance at the lever." * * * * * But through the wall behind it the vast creature, not unnaturally, refused to go! It darted from side to side. Backward and forward. Up to the wall, only to back bewilderedly away from it. And constantly the tubes flicked their blistering, maddening rays along its monstrous sides and tail, as the Earthmen tried to guide it into the wall. "Hope there's enough left of it to do the trick," said Brand, white-lipped. The monster was smoking in a dozen spots now, and several of the hump-like scales on its back had been burned away till the vast spine looked like a giant saw that was missing a third of its teeth. "God, I'm thinking we'll kill it before we can drive it through that wall!"