"Panic is the Enemy!¹¹  A dozen blossoming flares flashed in the microsonar screen at once.
 It was the Fleet, replying to the Killer's fire. There was a burst of flares to starboard, a burst to port, a burst above.
 Joe Trencher wheezed triumphantly: "Missed us!"
 "That was no miss!" I rapped out. "We're bracketed, Trencher! That was a salvo from the Fleet unit to warn us to halt and cease offensive action—otherwise, the next salvo will be zeroed in on us!"
 He choked and rasped: "Be quiet!" And he cried
 orders  to the other amphibians, in the language I could not understand.             The Killer Whale leaped and swung, and darted around behind the wreck of the dome, into the patterned caverns and fissures where the saurians maintained their breeding place. The Killer swooped into a crevice near what had once been the base of the dome itself; in the microsonar screen I could see the looming walls of the crevice closing in behind us and below. I thought I could see things moving back there—big things. Big as saurians....

            But at least the Killer was out of sight of the Fleet. Gently it dropped to the rocky floor of the cut. There was a sharp, incomprehensible order from

            Tren-cher, and the whir of the motors, the pulse of the pile-generators, stopped.
 We lay there, waiting.
 The chorus of ragged breathing from the amphibians grew louder, harsher. No one spoke.
 All of us were watching the microsonar screens.
 The Fleet was out of sight now—hidden behind the rimrock and the shattered remains of the dome.
 The dome itself lay just before us. So short a time before, when Bob and I had raced up to give the warn-ing, it had stood proud and huge, commanding the en-trances to the breeding caves of the saurians. Now— wreckage. A few odd bits and pieces of metal stuck jaggedly above the ruin. Here and there there was a section of a chamber, a few square yards of wall, that still seemed to keep a vestige of their original shape. Nothing else.
 Joe Trencher had said that what the Crakens needed was a tomb. But this was their tomb, here before us— theirs, and the tomb of Roger and Laddy and my loyal, irreplaceable friend Gideon as well.
 Joe Trencher broke into a ragged, violent fit of coughing.
 I stared at him, watching closely.
 Something was going on behind that broad, contorted face. There were traces of un-guarded emotion—unless amphi-bian was beginning done—and to realize that there was no more hope for him than for us.
 expression, moments of I missed my guess, the to regret what he had  It was a moment when I might risk speaking.       I walked up to him. He glanced up, but not a man among the amphibians moved to stop me. I tried to read what was behind the glowing, pearly eyes; but it was hopeless.

            I said: "Trencher, you said there were two other men you could trust. Were their names both—Eden?"
 He scowled fiercely—but, I thought, without heart. "Eden? How do you know their names? Are they enemies too?"
 I said: "Because my name is Eden too. One of those men was my father. The other—my uncle." Trencher scowled in surprise, and hid behind his spray of salt water. I pressed on: "You said you could trust them, Trencher. You were right. My father has passed away, but my uncle still lives—and it was because he helped me that I was able to come here. Won't you trust me? Let me talk to the Fleet commander on the sonarphone—see if we can work out truce terms?"
 There was a long moment of silence, except for the wheezing and choking of the amphibians.
 Then Joe Trencher put away his salt spray and looked at me. He said bleakly: "Too late!"
 And he gestured at the microsonar screen, where the wreckage of Jason Craken's dome lay strewn before us.
 Too late.
 We all looked, and I knew what he meant. Certainly it was too late for anyone who was crushed in those ruins, under the weight of the sea. And in another sense, it was too late for Joe Trencher and his people—for they had certainly put themselves outside the pale of human law by causing those deaths.
 But—something was out of key, in those ruins. Some-thing didn't quite jibe.
 I looked, and looked again.
 One section of the ruins was intact. And—it glowed with the foxfire of a working edenite shield.
 And from it was coming an irregular twinkling light. It was faint, reflected from some halfhidden viewport; but it was no illusion. It was there, blinking in a complicated code. Complicated? Yes—for it was the code of the Sub-Sea Fleet; it was a distress call!
 They were still alive!
 Somehow, they-had managed to get into one section of the dome where a functioning edenite shield had survived the destruction of the rest of the structure!
 I said to Joe Trencher: "This is your chance, Trencher. They're still alive in there—now you can make your decision. Will you surrender to the Fleet?"
 He hesitated.
 I think he was about to agree.
 But two things happened just then, that made his agreement to give up and submit to the laws of the Sub-Sea Fleet an academic matter.
 There was a white rain of explosions patterning all over the microsonar screens—more than a dozen of them. The Fleet was moving in to destroy us!
 And in the rear screen that peered down into the crevice in which we lay, something stirred and quivered and came racing toward us, huge and fast. One of the saurians was attacking!

            That was a moment when time stopped.
 We stood frozen, all of us, like chess pieces on a board, waiting for a player to make a move. Joe Trencher stared at the screen in a paralysis of indecision, and his amphibi-ans waited on his signal. Bob and I—we watched. We watched, while the bright exploding fury of the Fleet's missiles churned the deeps into cream around us and the Killer Whale shook and quivered under the force of the surrounding explosions. We watched, while the giant, hur-tling figure of the saurian came arrowing in upon us— closer and closer, looming huge and frightful in the sonar screen.
 Frightful—and not alone! For on its back was a slim figure, bent low along the monstrous back, driving it forward with an elephant-goad.
 It was the sea-girl, Maeva!
 Joe Trencher's hand hovered over the firing control of his jet-missile gun.
 I could not understand why he didn't shoot.
 One of the amphibians screamed something in a shrill, furious voice at Trencher—but Trencher only stared at the screen, his opaque pearly eyes filled with some emo-tion I could not read.

            Crunch.
 The speeding, raging figure of the saurian disappeared from the screen—and a moment later, the Killer Whale shook and vibrated as the plunging beast rammed

 us.       We all tumbled across the deck—it was that heavy a blow that the rampaging saurian had dealt the Killer. In the screen I caught a glimpse of the saurian bouncing away, wildly struggling to regain its balance, beating the water with its clumsy-seeming oars of limbs. It had been hurt—but it was still going, and its rider, the sea-girl, still had kept her seat. It had been hurt—but so were we.

            The Troyon tube lights flickered, dimmed, and bright-ened again. Ominous warning! For if the power went— our edenite shield would go as well.

            The amphibians were silent no longer. There was a chattering and screaming from them like a cage of ma-dened monkeys. One of them was scrambling across the tilted deck toward the missile-gun controls. Joe Trencher picked himself up and made a dive for the other amphibi-an. But Trencher was groggy, slow—he had been hurt; the other pearly-eyed man turned to face him; they strug-gled for a second, and Trencher went flying.

            The amphibian at the gun spun the controls as, in the screen, Maeva and her strange mount came plunging in for another attack.

            There was scarcely time to think, in that moment of wild strife and confusion. But—Bob and I were cadets of the Sub-Sea Academy and we had learned, what gener-ations of cadets before us had learned so well, that there is always time to think. "Panic is the enemy!" That motto is dinned into us, from the moment we arrive as lubbers until Graduation Day.

            Never panic.
 Think—then act!
 I whispered to Bob: "It's time for us to take a hand!" Trencher and the other amphibian were locked in a

            struggle over the controls of the missile-gun; one shot had been fired, and it seemed Trencher was trying to prevent another. The remaining amphibians, half a dozen of them or more, were milling about in a state of confusion.
 We hit them full amidships, with everything we had.

            It was a fierce, bloody struggle for a moment. But they were confused and we were not; we knew what we had to do. Some of them wore sidearms; we hit them first, and got their guns before the others could come to their senses.

            And the fight was over almost before it got started. Bob and I had the guns.
 We were masters of the Killer Whale!
 We stood there, breathing hard, guns drawn and leveled.
 Joe Trencher cast one bright, maddened look at the microsonar screen and came toward us.
 "Hold it!" I yelled. "I'll ------ "
 "No, no!" he cried. He skidded to a halt, gestured at the screen. "I want—I only want to go out there. To help Maeva! Don't you see?"
 I risked a glance at the screen.
 It was true—she needed help. That one wild shot from the missile gun had struck her mount, Old Ironsides. It was beating the water to froth—aimlessly, agonizedly. The girl herself was gone from its back—stunned by the gun, perhaps, if not worse. Even as we watched, the monster began to weaken. It turned slowly over and over, beginning to sink....
 Bob whispered: "It may be a trick! Can we trust him?"
 I looked at Joe Trencher, and I made my decision. "Go ahead!" I ordered. "See if you can help her—we owe her that!"
 The opaque eyes glanced at me for only a second; then Joe Trencher flashed past me, toward the lock.
 He paused, while the inner door of the lock was open-ing. He gasped: "You've won, air-breather." He hesitated. "I—I'm glad you won."
 And then he was gone. In a moment we heard the thud of water coming into the lock.
 I ordered: "Bob! Get on the sonarphone to the Fleet. Tell them to hold their fire. It's all over—we've won!"

 And that was the end of the adventure of the Tonga Trench. We found our friends, in that little sealed cubicle that was all that was left of Jason Craken's castle beneath the sea. They were battered and weary—but they were alive. The sea-medics of the Fleet came in and took charge of them. It was easy enough to heal the bruises and scars of Gideon and Roger and Laddy and David Craken. When it came to old Jason, the medics could do little. It was not the flesh that was sick, it was the mind. They took him away as gently as they could.

            He didn't object. In his clouded brain, he was still the emperor of the Tonga Trench, and they were his subjects.

            Maeva came to see us off. She held David's hand and turned to me. "Thank you," she said, "for giving Joe Trencher his chance to save me. If he hadn't come to get
 me ---"

            I shook my head. "You deserve all the thanks that are going," I told her. "If it hadn't been for you and Old Faithful ramming us just then, Bob and I never would have been able to take over the Killer Whale.

 And Tren-cher himself helped. He wouldn't let the other amphibians shoot you—I don't know why."     She looked at me, astonished. She and David turned to each other, and then David looked back at me and smiled.

            "You didn't know?" he asked. "It isn't surprising that
 Joe wouldn't let them shoot Maeva ... since she is, after
 all, his daughter _ "

            The last we saw of Maeva she was swimming beside the ship that bore David and Bob and me, waving fare-well to the microsonar scanners.

            All about silhou-ettes returning to Tonga Trench. She looked oddly tiny and alone against the background of those dreadnaughts of the deep.

            She could not see us, but we waved back. "Good-by," said Bob, under his breath.
 But David slapped him on the back and grinned. "Don't say 'good-by,'" he ordered. "Say us in the screens were the long, bright of men-of-war of the Sub-Sea Fleet, station after ending the struggle of the ⁽au revoir.' We're coming back!"