Orca was the apex predator. The waters around Japari Park belonged to her and her alone. Of course she was willing to share the open ocean, the beaches and the tides, and of course she would be happy to see her friends enjoy them in peace - but anyone or anything that dared infringe on her territory would face consequences. Celliens were no exception.

Yesterday, Common Bottlenose Dolphin had heard something odd out past the Sunrise Harbor, past the undersea ruins and it couldn't have been anyone they knew. It was much too late at night, Dolphin said. It was much too deep.

Tonight's sun dipped low, and it had to be just past suppertime. A twilight gleam shimmered across the deep, dark blue of the Sunrise Harbor, reminding the Apex Predator of the color of her hair and the hue of her sleeves. Frothy saltwater licked at Orca's heels as the waves rushed over the sand-speckled beach.

Taking steps out to water, she let her legs soak, then her waist, then her shoulders until finally her whole body was submerged, soaked, all beneath the surface.

It was her duty to ensure that the oceans would remain calm, even if she had to do it alone while everyone was enjoying dinner. After all, it would be terrifying for the other marine Friends to return to a cellien-infested ocean. The last thing she wanted was to have her waters be contested by such vile, malicious creatures… she had to do something. These were her waters, after all. It was only right.

Orca sprang off the beachside bottom, launching along the ocean floor at speeds rivaled by none but the fastest of swimmers. The deeper she got, the darker the waters became. The darker the ocean grew, the harder it was to see the sand, the rocks, the debris, the coral, the seaweed and other undersea vegetation.

Orca closed her eyes. Her sight was useless when below a hundred feet.

As she came to a stop, the Apex Predator hovered in place, using her arms and legs to steady herself against the current. Her clothes flowed freely in the water, her hair taken by the chill of the deep.

And she listened.

Her underwater acoustic perception was among the best around, something she was proud to boast about with the others. California Sea Lion detested playing hide and seek with her for that exact reason. Of course, her elaborate sonar suite wasn't something she liked bringing too much attention to as it that would be pretentious, and no one in their right mind would want to be pretentious. But of all her talents, something so vital was something to take pride in.

With that, it was strange to find that she heard nothing. Just the sound of the waves above her, the echo of the current, the shifting of sands and a rumbling of what she assumed to be underwater fissures spewing heat.

Had Dolphin been lying to her? Maybe she had heard something that wasn't there. It was certainly easy to be paranoid in the dark. But Dolphin was also excellent at undersea listening, so…

Orca hesitated, thinking of what to do. If nothing was here then there was no reason to keep searching. But on the other hand, a cellien on the loose could cause a huge disruption or even injuries.

And that's when Orca thought of something. That humming she thought to be fissures… it had moved.

Listening intently with a focus towards the humming, she filtered out all other sound to the best of her ability. The ocean worked with her, the hum's echos reflecting off the seafloor and into her perception.

That's it. That humming wasn't a fissure as those couldn't move. But this object was moving from her right to her left, faintly and far in the dark. By now it was impossible to tell it's depth or distance but she knew its direction.

And it had to be a cellien.

"Eeeeeeep!"

Orca released a concentrated, high pitched call straight at the unidentified object. This was her echolocation, and as loud and sharp as it was, it was her tool of choice for underwater navigation and location.

"Eeeeep!"

The call returned to her, the ping traveling just a few seconds to reach the target and another few seconds to return to her. The echo revealed that it had to be a large creature, something that was but a handful of nautical miles away. That was bad… it was too close!

"WHHHHHPONG!"

Another sound, however thundering, had returned. It pierced the water and sent shockwaves ringing through Orca's fragile body. The sound wasn't letting up! It began repeating, blinding her only means of sight in the now-deafeningly dark ocean.

Taken completely aback by the barrage, Orca barreled to the surface, swinging her arms and kicking with her legs harder than she ever did in her entire life.

"WHHHHHPONG! WHHHHHPONG! WHHHHHPONG!"

Excruciating pain flooded her ears in the seconds it took for her to break through the waves. Her hearing, as powerful as it was, was incredibly sensitive. Her ears begun ringing as Orca splashed to keep afloat, the devastating sound unlike anything she had heard before.

She had to move, she had to get away from the sound… but she had to stop that cellien. It had sonar as well, it seemed, and a very intrusive and powerful one at that. Almost unnatural, it would have destroyed her hearing had she stayed beneath the waves for too long.

Plans, ideas, and worries splintered and danced through her mind as she bobbed up and down, up, down. She could hardly hear the pings anymore now that she was above the water, which looked as calm and natural as it did in the afternoon. There was not an inkling of an inclination that there was a fight to be fought, not with the oranges, reds and yellows painting the water in the light of a triumphant sunset.

As Orca had used sonar to detect that cellien, it was likely using sonar in return, to spot her. Her location must've been compromised… she shouldn't have pinged in the first place!

Treading water, the predator began drifting towards her foe. She was running out of options, and right now, time was not on her side. She was terrified to stick her head below as she knew she might be shocked by that horrible sound, but there had to be a way to fight back.

Orca felt a brush of exceptionally chilled water rush past her leg, and that's when an idea came to mind.

In the deep water there was a point in which sound reflected midway through. It was essentially a sound barrier, something she could exploit to hide from those aggressive pings and still stay under the surface. The cold layer, she called it - it was a point when the warmer water nearer to the top didn't quite mix with the colder water underneath. That temperature layer reflected sound, and Orca knew that could help ease the damage on her ears.

Taking the cold layer into account, the Killer Whale took a deep breath before breaking out into a powerful breaststroke. Pushing herself to her limits, Orca accelerated towards open water and away from Japari Park as fast as she could. She wasn't much of a fan of swimming on the surface, but this time she didn't have much of a choice. She had to get out there.

"WHHHHHPONG!"

The pings reverberated through her bones as she swam right past the cellien. The further out she got, the dimmer the sky became, and the crest of the sunlight dipped further and further below the Sandstar Mountain behind her.

After a handful of miles, Orca decided this was enough. She swelled her lungs with determination before taking a plunge into the dark.

It was fantastic to finally be immersed in her element again. Engulfed by the saltwater, Orca dove as deep as she could, taking care to listen for the cellien. She was going so fast that the rushing water made listening challenging at best, but on the other hand, she quickly realized that the cellien's sonar pings had to be directional. It was still turning around to face her and the worst of its pings were being sent out away from Orca, where it wouldn't hurt her just yet.

A rush of temperature flushed past her body from her head to her toes, and that's when she knew she passed the cold layer. Throwing her arms and legs out to help her come to a stop, Orca took a moment to relax. To pause. To listen.

Her eyes were useless. Blinking twice revealed the dark expanse of the deep, deep ocean, and so she let them close. The shutting down of one of the five senses only bolstered the rest, and with that her sense of sight molded into her ears.

She knew she couldn't ping again, not after how she alerted the cellien earlier. Silent, she felt the water between her fingers and the void beneath her feet.

There was the hum. There was the ping, too - but this time, it was passing far above her, above the cold layer.

To the cellien, Orca was gone. Invisible. It couldn't see her, it couldn't hear her… she truly was gone.

She couldn't approach it head on, but she had to take it down by hand. All celliens had a stone somewhere on their body, a nucleus of their life, and by smashing it the rest of the creature would fall apart. It was only a matter of letting the creature expose itself, letting itself get into a position where it was possible to strike.

Staying still was the best way of preserving the stealth she needed, but she did have to get close. Orca crept through the deep using light, soft strokes of the arms and legs. The creature's pings were trapped above the cold layer and she shouldn't be spotted by them, but if she made too much noise then it might still hear her.

The ocean floor must have been a long way away, but Orca kept imagining the world below to be nothing but empty water forever. After being underwater for so long she was used to the feeling, but it still nagged at her in the same way she was terrified of heights.

The humming of the cellien was close now. Its pings revealed it to be just about overhead, maybe only two nautical miles away. Orca was used to fighting celliens. They were everywhere, from the ruins to the Jungle, from PPP's stage to the savanna. Fighting was nothing new, but this? She had never taken on such a gigantic cellien by herself before. A cellien had never used sonar before. And she never knew such a thing could even exist - not without finding it with her own ears. Today was full of surprises.

"WHHHHHPONG!"

"Ahh!"

Orca cried out in pain, clutching her ears with the palms of her hands. It pinged her? How? She was below the cold layer!

"WHHHHHPONG!"

The cellien began descending, the pings as loud as they could ever be. It was still above the cold layer, that much was for sure, but for some reason the sound had arched down, directly below the layer where it had originated from. It pierced the cold and shot through the ocean - right into Orca.

Feeling the pain in her ears ten times more terrifying than before, Orca pushed herself to her maximum speed in an effort to get behind the cellien. If she could get behind it, she could escape the sonar, but would it be too late for her ears?

Using both her arms and her legs left her ears exposed to the blaring sonar, but she knew she had no choice. It wasn't long before she managed to escape the pings, pushing through to the rear of the cellien, but the ringing in her ears refused to go away.

She couldn't see. She could hardly hear. Orca hoped that her ears weren't bleeding, but at this point, anything could've happened.

Her ears were her most valuable asset… that cellien just crossed a line of no return.

Orca swam up to the side of the creature, opening her eyes to try and get a look at the cellien. Through the dark, murky waters, she could barely make out anything - but the cellien was right there. It was cylindrical with some sort of rectangle on the top. Two hardened fins poked out around the front of its body with a propeller stuck to the monster's rear end. The whole thing was enormous… terrifying to look at and terrifying to hear.

A massive eye entered her vision as the cellien turned. The eye of the enemy lie on the very front of the entire being, and it was a sight to behold.

Something so massive couldn't exist in reality… she heard rumors of an enormous black cellien on the mainland, but in the ocean? Facing it on her own? Did she even stand a chance?

Orca blinked, her eyes unable to do much of anything in the dark. She couldn't rely on her ears, either. But the beast was still moving and it was up to her to stop it now. There was no turning back - not without surfacing and admitting defeat.

She was the predator around here. Apex meant that nothing was to best her - apex meant that she was at the top of the chain. This cellien wasn't about to change that. It wouldn't.

Orca darted to the cellien's hull before grappling onto the side of the beast. It seemed as though it was alarmed by that, as it begun speeding up and accelerating deeper towards the ocean floor. The current rushed past the killer whale as she trailed along the side of the monster.

Her hands ran along the edges, eyes scanning for a stone in the dark. At this rate, it was only a matter of time before the stone would be found and there was nothing the cellien could do about it.

The cellien wasn't about to give up, however. It kept diving, but Orca kept keeping pace. Her hearing started to return, the ringing eased, ever so slowly, allowing her to focus.

The deeper the cellien dove, the more tight the world felt on Orca. The water pressure… if she held on for took long, she would be crushed!

Time was of the essence as Orca trailed towards the bow of the cellien. There was no stone in the rear. No stone on the front. What about that top protrusion?

Orca let go of the cellien for a moment, letting herself drift to the monster's tower. Searching the sides revealed nothing but smooth surfaces, but the top…

All of a sudden, Orca's exhausted ears picked up an audible crash. It wasn't that loud, but it sounded off into the dark, mirroring the sound of bubbles and rushing water.

Orca let out a peep, honing her echolocation towards the sound. Sure enough, she could hear a return - a tiny cylinder just shot out of the cellien!

It was like a miniature version of the mother. Tiny fins, a small propeller… it cruised through the water faster than the cellien. As it swept into the dark, Orca could hear it getting louder. Did it just turn around? It… it was coming right for her!

The assailant sped towards Orca, leaving her no choice but to let go of the cellien's tower. Letting herself flow freely along the monster's hull, the smaller projectile smashed right into the tower.

R-BOOOSH!

A mass of light and sound detonated against the beast, ripping and tearing into the tower. Orca barely missed being caught in the explosion, and with her heart racing she had almost been lost in the majesty of the sight before her.

What a brilliant display of fire and power… something she never thought she'd see in her life.

It seemed as though the search for the beast's stone was redundant. The detonation of the cellien had engulfed it's tower in its entirety, which had begun splintering into multiple enormous pieces.

Orca watched in what she believed was a mix of horror and curiosity as the cellien folded apart. Secondary explosions rocked the ocean, the bow of the beast suffering catastrophic damage as the propeller ceased to operate. Oil and air begain leaking from the gaping hole, all of the excess streaming for the surface.

The behemoth drifted down, down, down into the dark. With the end of the explosions came a round of darkness and one final return to the deep. A return to safety, Orca thought, watching it finally burst into a series of cubes.

As they sunk down, deeper and deeper, Orca wondered if that was the end of it. The darkness of the ocean had swallowed the beast whole. The endless, merciless expanse of water had swallowed one more.

Such a behemoth of a cellien left the Apex Predator both vindicated and most curious… how did it exist? Why was it here?

...Would there be more?


A/N:

What Orca called the 'cold layer' is called the thermocline, which is essencially what was described in this 'one shot.'

The submarine was a flight II Los Angeles class, which was sunk by celliens in the past before the cellien substance came in contact with the wreck, creating a cellien-sub. There must be an awful lot of wrecks around Japari Park... I would not be suprised if more man-made celliens came to be.

Thank you for reading - I hope you enjoyed!