Chapter One

Reysa stood impatiently at the edge of the fields of air, waiting for his herd of hydruka to finish their work. The Onu-Matoran knew that the creatures could not be rushed. Although tame, they were still highly temperamental. If they chose to be stubborn and not harvest the airweed, he would have a lot of explaining to do when he got back to the city.

Still, he wished they would hurry up. Looking like a cross between a crab and a scorpion, they moved slowly through the field, gathering the weeds one at a time. It wasn’t particularly difficult work — a Matoran could do it, easily — but only the hydruka could tell which weeds contained precious air and which did not. For Reysa and the other Matoran who lived in the underwater city of Mahri Nui, air was the most valuable commodity imaginable.

Reysa swam a little closer to the field, trying his best not to spook the hydruka. Like all Onu-Matoran, his eyes were well suited to operating in a low-light environment. There were few places darker than the outskirts of Mahri Nui. The only one Reysa could name was the watery region just below the city. The darkness there might as well have been a reflection of the hearts of its inhabitants.

That thought made him swim closer to the hydruka and wave his arms to urge them on. He had foolishly lost track of how long they had been at work. If the safe hour was almost over — or worse, had already passed — every moment he spent this far from the city put his life at risk.

There might be something down below right now, watching me, he thought. I know how they watch, with those cold, milky eyes. I know what’s happened to those who didn’t make it back before safe hour ended… or I can guess.

He looked around but could see nothing out of the ordinary. Just the vast underwater world and a few schools of fish swimming idly by… not even any marine predators around. That was good. It meant there might still be time left in the hour. If the hydruka would just hurry up…

Come on! he shouted in his mind. What’s taking so long? If they weren’t simply Rahi, I would think they take some pleasure out of making me worry like this.

He heard a sharp noise from below and to his left. It stood out from the constant cacophony of sounds that filled the undersea realm, for it sounded like metal scraping against rock. Reysa wondered if it might be some piece of equipment that had drifted away from the city and become lodged in the rocks below. Maybe it would be something worth recovering.

Mahri Nui and the fields of air rested on a large, mountainous slab of rock that looked like an upside-down triangle. The base of the triangle was at the top and was where the city was located. The point of the triangle was at the bottom, wedged between some massive, curved bars of rock. If it weren’t, or if it ever became dislodged, Mahri Nui’s chunk of solid ground would tumble end over end to the very bottom of the ocean, taking all of the Matoran with it.

Reysa began to swim toward the edge of the undersea island. When he was almost there, he stopped. What am I doing? he said to himself. I’ve heard enough tales of “quick peeks” over the side that led to disaster. Whatever is scraping against the rocks can just stay there, as far as I’m concerned. I just want to get these hydruka and their harvest back to the city.

He turned away from the precipice, normally a good thing. After all, if beyond the edge lies danger, reversing your course and moving away from it would keep one safe. Except, of course, that it makes it impossible to see what might be coming after you from behind.

That was why Reysa was so surprised to feel a tentacle wrapping around his chest. It began to pull him back toward the edge as if he were no more than an errant piece of airweed. He swam, he kicked, he struggled, but all he accomplished was to panic the hydruka.

Reysa was over the edge now, with nothing but black water below him. He beat on the tentacle with his fists, then kicked backward. His foot struck something solid — it had to be the body of the creature!

He looked over his shoulder, hoping to at least have the satisfaction of knowing what was dragging him off to his doom. He looked, and he saw, and then he discovered a basic fact of life (and death): The problem with being underwater is that you can’t scream.

Defilak walked silently into the Matoran Council chamber. Located deep inside the Mahri Nui fortress, it was the largest single room in the entire settlement. The huge, domed ceiling featured crystal skylights lined with lightstones whose gleam reflected off the water all around. The walls of the chamber were lined with “Mata Nui’s gifts” — tools and artifacts that drifted down through the ocean to Mahri Nui every month, from no one knew where. Those items that could be put to use were given to the Matoran most in need, and the rest were brought here to be mounted.

But what truly gave the chamber its air of solemnity and importance was its purpose. Here every Matoran citizen would gather once a month to discuss any issues that threatened the safety of the city. Plans were made, decisions arrived at, and hopefully everyone left knowing exactly what the city needed them to do. This was essential to survival in a hostile environment. Leadership of the Council was rotated among the citizens, and this month Defilak was in charge.

He took his place on the raised platform and looked out over the assembled Matoran. His friend Gar smiled and nodded encouragement. Defilak was many things — an inventor, a scholar — but a public speaker he was not, and he dreaded the experience.

“Um… fellow Matoran… um,” he began. “This talk-meeting will, uh, come to order, please.”

The Matoran crowd continued to talk among themselves, few even noticing that Defilak was standing there.

Defilak tried again. “Hello? Could you all stop the chatter-noise, please, so we can get started?”

The murmur died down a little bit, but not by much. Most of the citizens were still deep in their own private conversations with their neighbors.

Okay, I tried it the nice way twice, Defilak said to himself. Now I do it my way.

He slammed his sword down hard on the table, and yelled, “Shut up!”

The crowd quieted instantly and turned to face him, looking shocked. Matoran Council meetings didn’t usually start this way, although they occasionally ended with a lot of yelling and now and then a fight.

“That’s better,” said Defilak. “Does anyone have any word-news to bring before the Council?”

One Po-Matoran rose. “I do. Two of my friends disappeared today. One was taken from the fields of air, and one tried to reach the world above and never came back… that makes five who have vanished in the last two weeks. What are we doing about it?”

Defilak paused before answering. Working in the fields of air was always treacherous because it exposed Matoran to whatever lurked outside the city. But he had thought the residents had enough sense by now not to try to head for the surface. Even if they didn’t run out of air, the change in pressure would kill them.

Finally, he said, “Gar? What’s the status of our defenses?”

“The razorcrabs are dispersed all along the borders of the city,” Gar replied. “The thornplants are intact. Sea creatures have made probing attacks at a few of the outlying shelters, but we drove them back. No organized assaults on the city in two months now.”

“Then why can’t we travel outside the city in safety?” one Matoran in the crowd demanded.

“That’s right!” said another. “We know something is out there, hunting us, killing us, trying to seize and destroy our city. And all we’ve done is hide in our shelters and hope they go away! Why don’t we fight?”

A Ta-Matoran rose to speak. “I wish we could fight and bring down our enemies. But how do we find them? They might be anywhere in the black sea below us, a region they know and we don’t. There might be a dozen of them or a hundred. What have any of us ever seen? A tentacle? A claw? Sea life that might be acting like an organized army, or might not? I will be the first to volunteer to fight for Mahri Nui, but first, show me what to fight!”

Defilak gazed up through the skylight windows. The slight blurring of the lightstones’ glow showed where a thin bubble of air surrounded the building. That bubble, so vital and so fragile, symbolized Matoran life in Mahri Nui. They were hanging on here, just barely, never knowing when the next attack might come or if the fields of air might suddenly turn barren. Just as they did in the safe hour, every Matoran spent his life waiting for the moment that Mahri Nui’s time would run out.

It had not always been this way, he was certain. Just about all of the Matoran had some fragmentary memories of a life on the surface. Some of the memories were pleasant ones, others disturbing and frightening. Regardless, on the rare occasion someone was able to string together a coherent recollection, it was treated as a major event.

But his job was to focus on the here and now. Mahri Nui was under the sea and beset by enemies, whose identity and purpose were still unknown even after centuries of warfare. The Matoran could remain “secure” inside their air bubble protected shelters and wait for the enemy’s next move. Or they could go out and find the one weapon that might help them: knowledge.

Defilak rapped his sword three times on the table, indicating it was time for a vote. “I propose a scout-expedition into the black water, to be led by me,” he said. “We will quick-learn whatever we can about what’s down there and then return. I call for a vote.”

Those who supported the measure raised their right hands, those who opposed raised their left. Defilak’s proposal passed, though by a closer vote than he had expected. It seemed many of the citizens preferred staying quiet and not antagonizing whatever lurked beyond the city.

“Done,” said Defilak. “I need volunteers. We will leave as quick-soon as possible.”

“Wait a minute,” said Gar. “How do we get down there?”

Defilak smiled. “Oh, I think I can help with that.”

Kyrehx, a Ga-Matoran sentry, stood on guard on the borders of the city. A single step would take her outside of the air bubble and into the ocean, where she would be prey to ocean currents and sea predators. Although a personal air bubble would allow her to breathe for a short time, it was doubtful she would survive outside for long.

Not for the first time, she marveled at the way the air bubbles worked. Permeable enough to allow objects to pass through, they somehow managed to keep the sea out. Had Mahri Nui not crashed so near the fields of air, unleashing scores of small bubbles, no Matoran would ever have survived long enough to create bubbles around the buildings and pump the water out.

Unfortunately, the bubbles had a finite existence. Unless reinforced, they would eventually begin to shrink and then disappear completely, allowing the sea to flood entire buildings. It was only the air harvested from the fields by the hydruka and fed into the bubbles that allowed Mahri Nui to remain intact and habitable.

Something caught Kyrehx’s eye. An object was floating down toward the city. Gifts from the Great Spirit Mata Nui were not due for some days, so she assumed it was just a piece of debris. That assumption was weakened when she noticed the glow around the artifact. It vanished completely when she heard something call to her in her mind.

Heedless of the danger, she propelled herself off the rocky surface and through the air bubble. The object was just seconds away from drifting down past the edge of the undersea island and disappearing into the black waters below. She swam faster than she ever had before and grabbed it, then turned and raced for the safety of the bubble.

It was only when she was back at her post that she took the time to examine her find. The light that surrounded it was unearthly, somehow both frightening and calming at the same time. Energy surged from it, so that she felt as if she was struggling to hold on to an electric eel.

Kyrehx’s eyes widened. She was holding a Kanohi mask, one she had never seen before. It was no ordinary mask, she could tell that already, and she knew that she must bring it to the Council at once.

What she could not know, as she rushed for the Council chamber, was that she was carrying the legendary Kanohi Mask of Life. Nor could she comprehend that its arrival would herald the beginning of the end for Mahri Nui.

The dull, white eyes of a Rahi squid narrowed at the sight of the Ga-Matoran sentry passing through the bubble into the ocean. It was hungry for life energy and here was a Matoran offering herself up as a meal. It started to propel itself through the water, ready to strike.

Then the squid stopped. The Matoran had grabbed something drifting in the water. Even with its limited intelligence, and at a great distance, the creature could sense power. This was something that would need to be reported to its master.

It darted down into the black water, heading for the deepest parts of the Pit.