Author's Note: Wow, it's been a long time since I updated this story, huh? Well, this one and some of my other stories will be updated once my muse for them comes back. But now, get reacquainted with Things Unseen. A reviewer brought up an interesting point, so I apologize for not clarifying it sooner. In this universe, April is not half-alien, as this story was written before the revelation that she's half-Kraang. So she's 100 percent human in this, just having unique genetic coding but it does not provide her immunity. Anyway, Leo goes to the old lair as part of a monthly ritual, and recalls what happened to Splinter, but he may not be alone, and a certain player comes back into the fold. Rate and review!

Chapter 4: The Pain of Loss

It was a huge risk, but one he wanted to take. After all, there was no honor in disregarding loved ones who have passed on. Leo left in the middle of the day, when Donnie usually didn't have any drones out, and headed for a route he forced himself not to forget. Mikey was safe with Raph, so he had no need to worry. Of course…that didn't mean they wouldn't worry about him. He went alone for one thing, and he also went without his old T-phone. If anything happened, his brothers wouldn't know until it was too late.

He always did this at least once a month ever since they left the sewers. He would always come alone, ignoring the danger, and go to the same place every time. He had his swords ready just in case he ran into trouble…almost funny that they didn't get much use anymore except for the more difficult hunts. Often times, he just stuck with knives or arrows. But now…now they would probably be back to full-function again very soon.

After all…he along with the others felt like Donnie started to get even more desperate in his hunt.

Leo found the all-too-familiar manhole cover and pulled it off before hopping down. He sniffed the air, grimacing a bit; the sewers didn't have the usual smell anymore. Instead of the typical sewer smell, the tunnels and water smelled more and more of death and rot. He always remembered to never, under any circumstance, come into contact with the sewer water or any water that could go through the tap. After all…that was how Splinter… He couldn't make himself think about that now…he couldn't let his grief get in the way and leave him vulnerable. So he walked along the path free of water and made his way to the abandoned subway depot.

"Is that cure coming along or not!?"

Donatello scrambled with several chemicals, dropping two test tubes overflowing with corrosive liquids onto the floor with loud splashes and shattering glass. "How about YOU try making an antidote when Sensei could perish any SECOND, Raphael!?" His hands holding a beaker and test tube began to tremble violently until he accidentally spilled some serum over his hands. "DAMMIT!"

"Donnie, calm down! You don't work well under pressure, remember!?" Leonardo snarled. He couldn't say that he worked well under pressure himself, so he instantly felt the guilt of being hypocritical. Of course, why wouldn't they be stressed? Splinter…Splinter contracted the virus and could die at any second. He was in his room and he looked horrible. The moment the mutation occurred, Mikey threw up just from the gruesome sight and Raph barricaded himself in his room for the rest of the night. Their own home wasn't safe anymore from this pestilence…

Tests performed by Donnie concluded that the virus was in the water supply, including the water rushing through the sewage system. So they knew that going into the water or drinking from the tap was forbidden; boiling the water wouldn't even completely kill it. So now they had to make plans to acquire bottled water and bottled drinks. But first…they had to cure Sensei and quick. If they couldn't cure him…at least they could try and make his final moments a little more comfortable.

Leo threw on his protective gear and went into Splinter's room to see his father, possibly for the last time. Terrible was an understatement for how he looked…the mutation caused multiple malformed limbs to jut out of his torso, his tail to split, and his muzzle to misshapen to the point he could barely talk. He twitched every so often, and a few hours ago when Donnie examined him, his skin felt like Jell-O and his insides felt like they were comprised of slush that slowly melted into water. Any gloves or other materials used to examine him were promptly incinerated under Donnie's command to avoid accidental contamination.

"Sensei…" Leo greeted quietly, swallowing the lump in his throat so his inner turmoil wouldn't break the surface. That proved to be in vain as tears dripped into the rims of his protective goggles. "Donnie…Donnie's working on a cure…but I don't know if he'll finish it in time."

Splinter wheezed, reaching his trembling and still-functioning hand over to touch his son's gloved one. Even with being at death's mercy, he still wanted to show his son that he loved him. "L-L-Leeoo…naaard-d-ooo…m-m-my…s-s-son…" He paused and felt some of his teeth break off in his mouth, feeling more like the texture of a wet sponge. "G-G-Goooo…do…not…w-w-worry…for me… S-Save…everyone…e-e-else…"

"S-Sensei…" He couldn't fight the battle anymore, and Leo freely broke into sobs. He wanted to hug his father, but knew he couldn't unless he wanted to suffer the same fate, even with the gear on. He just patted his rubbery hand and mumbled, "…I-I love you, Father…"

"A-As…do…I…my s-s-son…your…b-brothers…too…" Splinter garbled out. "G-Go…tell them…I-I…l-love th-them…"

Leonardo noticed his father's sides. Despite the grotesque extra limbs, he could clearly see Splinter's sides begin to sag and bloat. This was a symptom indicative of when a victim to this virus was getting ready to die; Donnie explained the sagging and bloating were a sign of the organs and bones liquefying. Splinter was dying…he had to get out of the room and tell the others. He forced himself to pry his blue eyes off of the rat's garbled, seizing form and leave the room, closing the door tightly.

He slid down to the floor and closed his eyes in shock, hearing his father, his sensei, begin to thrash and choke on his own watery innards. Those noises stopped as soon as they began, and came the sound of water collapsing and hitting the floor along with something slimy slapping the ground. It was then that the other turtles walked to the door and saw their brother sobbing.

"…Leo?" Mikey asked quietly, his eyes immediately going for the door. "Is…Sensei…"

Leo didn't have the strength to bring his eyes to stare upon his brothers. All he managed was to mumbled out in a strangled voice, "…Sensei's gone…"

Donnie was the first to have his heart drop into his stomach, pushing past Leo in a frenzy to open the door and see the evidence himself. Raph of course forced Mikey to turn away should the sight be revealed to all. They had to practically torch Splinter's body, but they would at least give him as proper of a funeral as they could. And then came a new nightmare…a set of strangled coughs coming from another room. Ignoring the hazard that was Splinter's corpse for the moment, they rushed into the main area of the lair to see who the coughs came from. Casey was out looking for survivors, so the only other person it could be was…

"…April?" Donnie dared to address her, fearing speaking louder would shatter something.

Right in the center of the lounge area, the area they always sat and watched television in the innocent days…April stood hunched over with her hand underneath her chin…her nose and mouth oozing with pale blue fluid mixed with blood.

Leonardo got to the familiar turnstiles, now covered in rust and mildew as a result of the lack of usage. He could still remember the way they clicked whenever one of them stepped through…something he never took for granted ever again. He hopped over them and took in the surroundings, comparing them to how they once were. Ever since they left, what was once the lair was now in shambles. The television remained on the floor and sporting a large, deep crack in the screen. All of the food in the fridge was surely rotten, and anything in the freezer now just balls of frost. He glanced at the floor and saw aged blood stains…and he could see obvious pieces of bone sticking up out of the water…bones that once belonged to a good friend. He didn't want to think about how he died; all he wanted was to pay respects and then get back home.

He remained careful of where he walked, not touching any water he saw, and he went straight for the hall that led to the dojo…and Splinter's room. He made sure to pay a quick visit to the rooms he and his brothers once occupied to get that wave of nostalgia he craved. His room was just as he left it; sheets askew and a few pieces of his action figure collection on the floor. The other rooms were just as much of a mess…well, maybe not Donnie's, since he barely slept in it to begin with.

When he got to the dojo, he found the tree showing signs of withering. No one had been tending to it like required, of course, though Leo brought water from bottles and used that to nourish the tree. Not today, though…the tree would have to wait. Using the tip of a hunting knife, he stuck it and used it to open up the door to Splinter's room. There it was…the makeshift shrine made to commemorate his memory. Photos lay strewn about of their Sensei; they weren't like that before. In fact, Leo walked closer and found the photos to be ripped; the only pieces that were spared were ones that had Splinter, April, and…Donatello? A cold feeling ran through the blue-banded turtle's blood. Someone was here…and that someone had to be Donnie.

"No…" Leo mumbled and shook his head. "T-The urn with Sensei's ashes are gone…why didn't I notice sooner?"

In the center of the shrine once stood a faded-silver urn that the turtles placed Splinter's ashes in soon after they cremated him. Now it was gone…and there was only one possible culprit.

Donnie.

Leonardo froze when he heard something metallic creep around on the floor behind him. He immediately placed his hands on the handles of his swords when the noise got closer, and his eyes and head slowly turned to the source. Finally, he jerked his head, and found one of the familiar robotic menaces that were of his renegade brother's creation. The creature let out the cry of a Mouser before charging at him with deadly intent to kill.

An alarmed blared on the primary computer monitor, prompting the purple-banded turtle to stop staring at the silhouettes in two tanks and head straight for the keyboard. He typed a few keys with great concentration until a live video feed popped up. Looks like the drone he placed at the old lair picked up something; it could've just been a rat or some other animal looking for food. The video jerked around; the drone had to be attacking something. Strange for it to be acting so aggressive for some miniscule vermin. Well, that's the thought he had until the target came into focus. His tired auburn eyes widened when he saw an all-too-familiar face through the optical feed and the fear written on it.

Leonardo.

His chapped lips slowly curled into a morbid grin, and a quiet echo of laughter followed. The quiet echo quickly grew to a loud chorus, causing him to lift his head back to get it all out. "GYAHAHAHAHAHAHAHAHAHAAAA! How stupid of you, Leo! You came all by yourself to our old home! YOU MADE THIS TOO EASY!" He grabbed his old Bō staff and made the rusty blade slink out of its hiding place. "Time for a little family reunion, brother dear~."

Leo yanked out his katanas and dodged the metal chimera at a feverish pace, almost getting nipped on the leg by the thing. The drone screeched louder and kept on his heels, itself dodging the blue-banded turtle's blades. It finally managed to get at his shin and tear through the fabric of his pants before taking a small chunk of flesh with it. The blue-banded turtle yelped in pain, but stood his ground against his attacker. The creature scattered the snipped and sliced photographs on the ground, and that seemed to strike a nerve in Leo. Finally having enough and with a cry of pent-up frustration, he drove his blade into the center of the machine's head, off-lining it instantly. Panting at a slow rhythm, millions of thoughts ran through his head.

That thing had a camera on it. Donatello more than likely saw him. Now he knows at least one of them is still alive and possibly near wherever he was staying. He had to warn Raph and Mikey…then they would have to pack up and find a new location to live. But if it came to it…he would have no choice but to kill his own flesh and blood. Ripping a piece of his pant leg and wrapping his wound, he sheathed his katanas and bolted, although it was hard with a limp. Now he had to avoid the water more than ever; an open wound would bring greater chance of infection.

Then a much sadder thought crossed his mind. Because Donnie had a drone set up here, maybe more…he could never come and pay respects to their father ever again. Worst of all, his estranged brother more than likely had the precious urns containing his ashes; the only way to get them back would have to be prying them from his cold, dead hands. How was he going to explain this to Raph and Mikey? As long as he got back to them alive, that is. He bolted out of the old lair and managed to reach the ladder going to the manhole cover, climbing up and pushing the lid off. Seeing nothing around, like old times, he slid out and managed to get to a corner, stopping to catch his breath. This day couldn't possibly get any worse…it couldn't.

"…If we have to move…where could we even go?" Leonardo asked himself, silently limping down the street and around corners. "We don't even have a way to get out of Manhattan anymore…"

He paused at a crumbled building and looked up. Second Time Around…the store right next to April's apartment. Closing his eyes and leaning his head against the ruins, he sighed and thought dearly of their first human friend…he missed her so much. He felt his eyes prickling with tears as he recalled her last moments with them…and then remembering what finally broke Donnie. He was about to settle with breaking down into pathetic sobs he held in for so long when he heard the sound of a blade ejecting out of a wooden object. He instantly froze, glancing to his right and seeing a blade right next to his head and a gash on his shell and shoulder. Then the smells…smells consisting of lab reagents, bleach, halitosis, and sweat. The breath on the back of his neck sent him into shivers and ragged breaths, hearing lips spread apart to form again.

"Long time, no see…Leonardo."