"As thou seest," she murmured, "there is nothing to be done. We can only resign ourselves to the fate that nears us, and enjoy as much as may be the few remaining rixas...." She glanced at me. The Professor's dry, cool voice cut across our wordless, engrossed communion. "I don't think we'll give up quite as easily as all that. We can at least try to outwit our enemies. If it does nothing else for us, the effort can serve to distract our minds." He drew from his pocket a sheet of parchment and the stub of his last remaining pencil. His fingers busied themselves apparently idly in the tracing of geometric lines. "Looking ahead to the exact details of our destruction," he mused coolly, "we see that our most direct and ominous enemy is the sea itself. When the city is flooded, we drown--and later the Quabos can enter at will." He drew a few more lines, and marked a cross at a point in the outer rim of the diagram. "What will happen? The Quabos force through the last shell of the city wall. The water from their tunnel floods into Zyobor. But--and mark me well--_only_ the water from the tunnel! The outer end, remember, is blocked off in their pressure-reducing process. The vast body of the sea itself cannot immediately be let in here because the Quabos must take as long a time to re-accustom themselves to its pressure as they did to work out of it." He spread the parchment sheet before us. "Is this a roughly accurate plan of the city?" he asked Aga. She inclined her lovely head. "And this," indicating the cross, "is the spot where the Quabos will break in?" Again she nodded, shuddering. "Then tell me what you think of this," said the Professor. * * * * * And he proceeded to sketch out a plan so simple, and yet so seemingly efficient, that the rest of us gazed at him with wordless admiration. "My friend, my friend," whispered Aga at last, "thou hast saved us. Thou art the guardian hero of Zyobor--" "Not too fast, Your Highness," interrupted the Professor with his frosty smile. "I shall be much surprised if this little scheme actually saves the city. We may find the rock so thick there that our task is hopeless--though I imagine the Quabos picked a thin section for help in their own plans." A vague look came into his eyes. "I must certainly get my hands on one of these monsters ... superhumanly intelligent fish ... marvelous--akin to the octopus, perhaps?" He wandered off, changed from the resourceful schemer to the dreamy man of scientific abstractions. The Queen gazed after him with wonder in her eyes. "A great man," she murmured, "but is he--a little mad?" "No, only a little absent-minded," I replied. Then, "Come on, Stanley. We'll round up every able bodied citizen in Zyobor and get to work. I suppose they have some kind of rock drilling machinery here?"