They passed through the bubble with a loud and unpleasant squelching noise, approaching the large, ornate building at a swift pace. Quite abruptly, however, they stopped, gazing at the structure ahead. The iridescent lights of Aleia’s glowing fins were thrown upon the dark stone, illuminating the completely smooth surface. There was no entrance.

“What now?” Milius asked, slightly desperately. As though it had been waiting for him to ask, the wall ahead of them suddenly split, sliding smoothly away to reveal a vast hole in the dead center. The water froze at the threshold, exactly as it had done in the arena of Phontus’s castle, as though an invisible barrier were keeping it at bay.

“That was . . . convenient,” Milius said, feeling both relieved and bemused, and he urged Lumeus onwards.

The dragon swooped into the hole, and a moment later they emerged into an enormous, water-free, silver-and-blue-walled room, lit by several merrily burning, blue-flamed candles posted around the room. The walls were studded with twinkling jewels and sea shells, and the floor was of highly polished alabaster, gleaming in the candlelight. The bubble around them burst as they entered, and Milius, Ariana, Shakil, Sirius, and Frederick dismounted, looking around. Oceannerva’s sapphire ignited at once, burning brilliantly, but every other jewel, just as they had during their time in the underground chamber, remained blank and dull.

“I feel something,” Shakil said suddenly.

“Yeah, well,” Milius said quickly, “don't go running off now. That's exactly what happened in the other one, and we ended up leaving as clueless as we went in. I say we take it slow, look through the rooms. . . .”

“Agreed,” Sirius said. “Besides, we don't know what could be in here. We need to be cautious.”

Ariana snorted. “You, talking about caution? It must be serious,” she said, half-laughing.

They set off through the corridors, moving slowly and quietly, the dragons trailing, one by one, behind them, Frederick staring around, his mouth agape. This second Catacomb — for Milius was sure that it was a Catacomb now — undoubtedly had some connection to Shakil, for his sword’s sapphire was glowing as brightly and as pointedly as Stormpyre’s emerald had all those weeks ago. It was also structured differently; it bore a great resemblance to Phontus’s castle, though there was no water.

They trooped along the corridors, opening doors and peering inside, a little apprehensively, though every room they examined so far had been empty. The corridor they were now walking along ended with another large hole, which they climbed through, and found themselves in a room that was otherwise empty but for a superb coral fountain in the center, spouting thick, luminous jets of multicolored fluid.

Milius was visited by a sudden, reckless desire to collect a sample of whatever it was that the fountain was spouting, to see if it had any special properties like the Nectar in the silvioterrace. But as though he had read his mind, Sirius seized his arm and shook his head, then marched him out of the room, maintaining his grip until the tinkling hiss of the fountain was lost to their ears. The room they entered now was much smaller than the previous ones, though still quite large. The walls were studded with sapphires and shards of silver, and in the center of the room was a humming ball of bright blue energy, suspended in a sphere of glistening water, which Milius was sure held the second half of the mysterious mirror, and which was no doubt obscuring a mosaic of the great blue dragon.

Milius, Sirius, Ariana, and Frederick fell back (some invisible barrier seemed to be present, barring them from approaching any further, though Frederick seemed intent on trying), as Shakil ambled forward. He stopped just short of the sphere of water, gazing at it in awe.

Milius watched, feeling both eager and apprehensive, as Shakil raised his arms and reached out towards it. His hands sank slowly into the water, a mere second from closing upon the ball of energy — and then, without warning, the pool of water turned black, viscous, trapping his arms entirely.

“What the — ?”

“Ah, the Dragonknights!”

The voice boomed throughout the room, reverberating from the walls and floor, loud, satisfied, and dreadfully familiar.

“Phontus!” Milius gasped, as Lumeus began to growl, sparks now dancing along his plates.

“Why, yes, indeed! You didn't really believe that our last encounter would be our last encounter, did you? Oh, how I've waited for this day! You humiliated me, stole one of my sacred Orbs, destroyed my Palace, and thought that you would escape barnacle-free?”

He gave a callous laugh that caused the walls to tremble ominously.

“How did you even find us? Oh, wait, let me guess — you were stalking me through your magical ceiling?”

“Quite,” Phontus said smugly. “I did tell you, didn't I? My palace may dwell underwater, but I'm quite aware of what goes on in the surface world. How I waited for you to return to the lake, seeking more Amphitrice for your ill mother. But you never came; alas, I almost gave up. But then I saw you, heading to Lake Tiberion, sporting your stolen treasure proudly! I hastened from my throne, determined to find you, to punish you, and now, at last, I've got you!”

“Talkative, isn't he?” Sirius said, sounding mildly interested.

“Uh, what exactly is going on?” Frederick asked. He did not look apprehensive, on the contrary, he appeared to be rather intrigued by this sudden and unexpected turn of events.

Milius ignored him. He was thinking furiously. Where was Phontus now? Was he alone, or had he perhaps brought a troop of his fierce-looking guards along with him? Or even — Milius’s insides squirmed at the thought — his giant squid?

“Uh, hello?” Shakil called, his voice jerking Milius out of his reverie. “I'm still stuck here!”

Sirius rushed towards him, Vulcatrix aloft, blazing with magical heat. He swung at the sphere; the blade ricocheted off as though he had struck rubber with a blunt point.

“Wha —” he sputtered, aghast.

“Oh, you won't get that off like that!” Phontus said, with another cruel laugh. “You think having that pearl makes you a master of the sea, boy? You have no idea what true deep sea magic looks like — but I can gladly show you!”

There was a sound like fingers snapping, echoing loudly through the room, and followed by a rushing, roaring sound. They waited, looking around to see what he had done. . . .

And then water burst into the room, gushing forcefully as though shot by a geyser, flooding the room with unnatural speed. Lumeus, Vrydius, and Verdona were submerged with pitiful squawks of terror, along with Ariana, Shakil, Sirius, and Frederick. But Milius managed to summon a protective bubble at the very last moment around himself, shielding him from the sudden eruption of water.

As the Knights, dragons, and Frederick flailed around, several of the enormous, monstrous creatures that Milius had seen swimming around in Phontus’s castle came flickering in. They looked like crosses between massive piranhas and eels, with wide, sinister, oddly blank eyes, and fangs like jagged rocks. Aleia, the only dragon unaffected by the upsurge, roared and rushed out towards them, but the strange markings over the fishes’ bodies flared. Electricity streaked from their luminous bodies, running through the water, and the blue dragon screeched with agony as the bolts connected with its glistening hide. The bolts flickered through the water, striking all the other dragons except Lumeus, who had sunk to the floor, his white marble eyes shut.

“No!” Milius looked around as the immense bodies of the dragons fell: the electricity did not seem to have affected the other Knights at all, but they were still struggling to breathe as they drifted in the water. He raised the Orb of Triton, directing its power towards summoning bubbles around their heads as well, but for the first time, the water seemed to be resisting him, as though it had come alive, rejecting his will.

Shakil was flailing around madly, his arms still trapped in the tarlike substance, trying to free himself; Ariana’s red hair was writhing around her head, like a flickering flame in the dark water; and Sirius was trying to heave the fallen Frederick from the floor. This shouldn't have been happening: he had summoned the bubble out of sheer instinct, but their visors should have been able to protect them, filtering the air from the water, though admittedly he did not know for how long it would work.

But that was not the case; Phontus was clearly doing something to the water. Milius could feel his presence, his magic, repelling his own will. Milius raised the Orb again, and with a tremendous effort that almost made him scream aloud, four large bubbles bloomed out of the water, coating the heads of his comrades.

They took deep, grateful gulps of the fresh air, gasping and spluttering, and looked around at the dragons. Milius tried to help them as well, but Ariana’s gasp of horror made him wheel around. The bubbles around their heads were slowly crystallizing — no, coralizing.

“Milius!” Sirius shouted.

Milius raised the pearl as a sheet of coral began to spread along his own protective bubble. It was agony. He was concentrating so hard that a sharp pain began to stab at his head, but the bubbles were barely responding to him. Phontus’s callous laugh sounded again, as loudly and clearly as if he was actually in the room beside them.

“I am the King of the Sea, you foolish child!” he snarled. “You think that petty rock can contest with my power?”

As he spoke, Sirius darted out towards the fish creatures and slashed one cleanly in half. The severed halves began to rot, the wounds still searing, but Sirius turned back to Milius and said harshly, “Don't listen to him! This isn't about magic, it's about will! Everything you told us about how the Orb works, it was about how you imposed your own force of mind over the water! You can fight him — you can beat him! You have to!”

The creatures, which had been floating, still and silent, as their master taunted them, suddenly fluttered out towards them, gnashing their awful teeth, clearly incensed by Sirius harming one of their allies. Ariana and Frederick, who had recovered and had been watching with a vague air, rushed out to Sirius’s aid, Stormpyre and the gleaming bone knife aloft. But Sirius was still barking at his cousin.

“The pearl still responds to you!” he said fiercely. “Even after all his talk about being the King, you can still fight him! Try!”

Sirius’s breathing was growing more ragged. His bubble was almost completely coated over now, obscuring his face, but Milius could feel his glare.

“And I think that's enough out of you!” Phontus roared suddenly. Ice began to spread over Sirius’s armour, as suddenly as the coral had started over his bubble, but he raised the still-blazing Vulcatrix and began to swing at his feet, passing the blade over his body so that the heat caught the ice; the ice faltered with every swipe, but it was spreading too quickly even for Vulcatrix’s powers to stop.

Abandoning the attempt completely, he looked up again at Milius, who was staring back, horrified.

“You have to stop him!” he said. “You're the only one who can fix this!”

“How?” Milius said desperately.

“The pearl — you still have the pearl! You can beat him!”

The ice completely coated him, freezing even the blade Vulcatrix.

“No!” Milius shouted.

Before he could say anything else, Ariana screamed. He looked past Sirius and saw that her sword had fallen from her hands; her bubble had completely turned to coral, and something that looked horribly like sea foam was spreading along her body. Frederick rushed over and tried to hack away at it, but the bone knife sank into the foam, which began to creep along his own arm as well, trapping him. The dragons were still incapacitated, and a new wave of monsters was zooming towards Shakil, who was still trapped in the rubbery, murky substance.

Milius’s eyes began to burn. “NO!” he screamed, so loudly that his voice cracked from the strain. He burst out of the bubble, the Orb clutched under one arm, and Palpatunde in the other. His rage spilled out of him, seeping into the pearl, which pulsed in response. Jets of hot water pelted at the approaching monsters, which shrieked as searing scorch marks bloomed on their scales.

He could feel Phontus’s resistance, like thousands of tiny hands in the water, trying to force him back, but he pressed onwards, his fury fueling the pearl, which propelled him forward. The water zoomed him from creature to creature, and he hacked and stabbed at every inch of them that he could reach, feeling the energy flow from their terrible bodies into the blade. And with a swift slash and a cry of anger, the blade ignited, regurgitating their own essences, blasting them apart.

He could feel Sirius, Frederick, Shakil, and Ariana in the water, alive, but only barely. He let out a guttural roar, and the pearl glowed its brightest yet. The light washed over the walls, over Frederick, over the other Knights, and he felt the water running over them again as the ice melted over Sirius, as the foam dispersed, as the inky substance encasing Shakil dissolved, and Milius turned to look at them.

Shakil’s hands closed upon the ball of energy, which glowed white for a single moment, then solidified and exploded; the shards fell as the water dispersed, streaming into the preexisting current, and Shakil, who looked confused for a moment, straightened up. He was holding, not a mirror, but what looked like half of a large stone tablet.

As Milius peered at him, anger still coursing through him, his vision suddenly went black; an unnatural darkness was stealing over him, obliterating every other sight; silence fell, a silence so loud it was almost deafening, and as Milius looked up, his eyes met another pair: enormous, white, and gleaming. . . .

Then the vision passed, and he was once again inside the Catacomb, his anger gone as though it had dissolved in the water.

“Is it over?” Ariana asked, looking around at the seemingly empty room.

“No,” Milius tried to say, but he couldn't get the words out; he felt suddenly, and strangely, tired. There was a deafening rumble from overhead — then the roof was ripped off, showering them with debris. King Phontus was looming over them, as large as he had been when Milius had first seen him, white-hot fury in every line of his face.

“Very well,” he hissed, glaring down at the Knights, who looked back up at him in horror. “Very well. . . . You will continue to defy me? Forget the powers of the sea, I'll crush you with these hands alone!”

And his enormous fist swooped through the water, a heavenly hammer, ready to demolish the Catacomb, and everyone inside.