I grinned up at him and he slapped me on the back--almost completing the choking process started by the salt water I'd inhaled. "That's better. Now--at it again!" I don't remember the rest of the tumult. The air seemed filled with loathsome tentacles and bright metal blades. It was a confused eternity until the decreased volume of water in the tunnel gave us a respite.... As the tunnel slowly emptied the pressure dropped, and the incoming flood poured squarely into the trough instead of half over it. From that moment there was very little more for us to do. Our little army--with about a fourth of its number gone--had only to guard the ditch and see that none of the Quabos caught the edges as they hurtled out of their passage. For perhaps ten minutes longer the water poured from the break in the wall, with now and then a doomed Quabo that goggled horribly at us as it was dashed down the hole in the floor to whatever awesome depths were beneath. Then the flow ceased. The last oleaginous corpse was pushed over the edge. And the city, save for an ankle-deep sheet of water that was rapidly draining out the vents in the streets, presented its former appearance. The Zyobites leaned wearily against convenient walls and began telling themselves how fortunate they were to have been spared what seemed certain destruction. * * * * * The Professor didn't share in the general feeling of triumph. "Don't be so childishly optimistic!" he snapped as I began to congratulate him on the victory his ditch had given us. "Our troubles aren't over yet!" "But we've proved that we can stand up to them in a hand-to-tentacle fight--" His thin, frosty smile appeared. "One of those devils, normally, is stronger than any three men. The only reason all of us weren't destroyed at once is that they were slowly suffocating as they fought. The foot and a half of water we were in wasn't enough to let their gills function properly. Now if they were able to stand right up to us and not be handicapped by lack of water to breathe ... I wonder.... Is that part of their plan? Is there any way they could manage ...?" "But, Professor," I argued, "it's all over, isn't it? The tunnel is emptied, and all the Quabos are--" "The tunnel isn't emptied. It's only _half_ emptied! I'll show you." He called Stanley; and the three of us went to the break. "See," the Professor pointed out to us as we approached the jagged hole, "the Quabos only drilled through the top half of their tunnel ending. That means that the tunnel still has about four feet of water in it--enough to accommodate a great many of the monsters. There may be four or five hundred of them left in there; possibly more. We can expect renewed hostilities at any time!" "But won't it be just a repetition of the first battle?" remonstrated Stanley. "In the end they'll be killed or will drown for lack of water as these first ones did." * * * * *