Navigating the library was more time-consuming than Dr. Mario would’ve liked, which was to say, even a little. Finding the door out of the basement was easy enough and he dashed up the flight of stairs beyond to the ground floor, only to find himself in a dimly lit hallway without any windows and several doors on either side. Furiously, he began throwing them open one after another hoping to find a window, but always found paper-littered desks, shelves of books, and a vending machine filled with brand drinks he wasn’t familiar with. He wished Luna hadn’t been in such a rush and had teleported him outside, but what was done was done. He continued checking doors until he finally found one that led into the main public area on the other side of which stood the front doors. He dashed over and practically jumped outside.
The streets of Canterlot were just as still and silent as before he’d entered the library. Over and over, he called out Celestia’s name as he dashed down every single alleyway and main street. Infected ponies could’ve heard him and jumped out to ambush him at any second, but the possibility of the viruses escaping Canterlot was a far greater worry. He still had a full bottle of megavitamins left in case things got hairy, anyway.
Finally, as he was nearing what must have been the train station judging by the stationary, pink engine across the platform, he heard a pair of great wings flapping overhead and looked up to see Celestia descending towards him; trailing behind her was her trio of guards.
“I had no idea you could shout so loudly, Dr. Mario,” she said as she touched down in front of him, followed by her guards. “How fares my sister? Why are you here?”
“There’s a filly that’s-a become possessed by the viruses,” Dr. Mario explained. “Luna is sure they’re heading for the reservoir through an old sewage system underneath the library. She wanted me to fetch you to get-a your help.”
Celestia’s eyes briefly flashed with surprise before she regained her calm demeanor and nodded. “Then let us hurry.”
She lit her horn and a flash of light filled Dr. Mario’s vision. Once it cleared, he saw the five of them were back in the library’s basement. All the victims he and Luna had cured were still sprawled around haphazardly, but looking far less tired and sickly than before, indicating the megavitamins were working.
Celestia turned to her guards. “Start getting everyone back to the castle’s hospital wing and make sure they get the utmost level of quarantine. Dr. Mario and I will follow after my sister.”
The guards all snapped a salute and got to work.
Dr. Mario led Celestia to the hole in the wall. She studied it with interest for a moment. “I remember when this was built about three hundred years ago. Clearly, we will need to conduct some renovations after this is all over. I wonder how this filly could know of this?”
“I don’t-a know,” Dr. Mario said. “But I have a hunch she isn’t doing this by choice.”
Celestia turned to him, confused. “What do you mean?”
“These-a viruses are sapient, that much is obvious by now,” he explained. “That one pony I fought-a with said she wanted help and she didn’t want to do what she was-a doing. I don’t know how, but the viruses might be able to control the actions of those they infect.
Celestia’s eyes bugged at hearing that theory. “Truly!?”
“It’s just a theory, but it’s the only one I can come up with.”
“Then we must make haste and aid this filly before the viruses are able to truly harm her.” She stepped through the hole into the tunnel. Dr. Mario followed right behind.
“Before-a we go, I have one question, Celestia.”
“Yes?”
“How long have you been alive?”
“Let’s just say I’m an overly-seasoned ruler,” Celestia said with a cheeky smile. “I’m also quite a good runner, so let me do this—” She lit up her horn and Dr. Mario gasped as he was pulled up off the ground, floating through the air before being lowered onto Celestia’s back. Next, she lit up her horn to illuminate their surroundings. “Hold on tight so you don’t fall off,” she advised.
Dr. Mario heeded her advice and wrapped his arms tight around her withers. Celestia folded her wings against her sides, lowered her head and scuffed her hoof against the tunnel floor. She then took off like a bolt of lightning, shooting so fast that Dr. Mario almost lost his grip on her. The tunnel walls whizzed past at breakneck speed under her horn’s light— after a short while, looking at them made Dr. Mario’s head swim, so he closed his eyes. They came upon a few intersections, at which points Celestia would stop for a moment to look between them before picking a direction and galloping like the wind again. Dr. Mario was too busy holding on for dear life to enjoy the thrilling sensation even a little.
Finally, the faint sound of running water reached their ears. A source of light illuminated the tunnel up ahead, rapidly growing bigger as they approached. They came out into a large chamber and Celestia stopped, letting Dr. Mario hop off her back. They both took in their surroundings. A canal ran the length of the chamber, leading into a large pool before continuing on the other side towards an opening that led to the outside, but transparent, midnight-blue barriers covered all the water.
“Luna!” Celestia called out.
“Sister!”
They turned to see Luna standing against the wall next to them, behind another barrier with her biohazard suit oddly torn to pieces next to her. A pink earth pony filly with a green mane was pounding against the barrier with her tiny little hooves, trying but ultimately dealing no damage. She stopped hammering against it to turn to them. A creepy, playful smile split her muzzle as she looked over Celestia before dipping when she noticed Dr. Mario.
“You,” she said with obvious disdain.
“You have nowhere to run to, viruses,” Celestia said. She lit her horn and cast a golden barrier over the entrance to the reservoir.
The filly laughed. “Your magic lets us multiply exponentially. Enough that we could take over your motor functions and force you to let us escape to the outside world through here.”
“And how did you find out about this place?” Celestia asked.
A new voice came from the filly, this one snarky rather than playful. “We sent out scouts to sweep the city when we escaped from him—” she finished with resentment clear in her voice as she pointed at Dr. Mario.
“Nothing about you viruses is normal, it seems.”
“It took you that long to realize this? And you’re supposed to be the ruler of this world?”
Celestia didn’t let the insult faze her. Instead, she, along with Dr. Mario, stepped forward with their bottles primed. “Would any efforts to negotiate fall upon deaf ears?” she asked. “Could you not be persuaded to cease your transgressions against my people?”
The filly laughed. “Never! We must spread far and wide, as is our mission!”
Mission? Dr. Mario was almost taken off-guard by the statement, but it was already beyond clear that these viruses were anything but normal. Right now, however, neither their motives nor origins mattered; they were a threat to the health of everyone in every world they entered, and so had to be stopped at all costs.
“I’ll-a use the megavitamins, Celestia,” he said.
Celestia nodded and put away her own bottle. She then lit up her horn and grabbed the filly with her magic, lifting her up into the air. Strangely, the filly put up no resistance. The sinister, knowing smile she wore was out of place, making Dr. Mario uneasy as he moved forward.
“Sister! Dr. Mario!” Luna called from behind her barrier. “It’s a trick!”
They both looked at her curiously. In the moment they were distracted, the filly reared back and blew a giant glob of multicolored snot at Dr. Mario. Pure, base instinct took over and he jumped out of the way, keeping his hand firmly clutched on the bottle. The glob of snot sailed through the space of air where he had been and splashed across the front of Celestia’s suit. The impact startled her, but she didn’t look fazed.
“Sister! Get out of the suit!” Luna cried, panic filling her eyes. “Get behind the barrier where it’s safe!”
Again Celestia looked at Luna curiously. Then her ears perked up as a faint sound of ripping fabric filled the air around her, growing louder with each second. Her eyes bulged and, in a flash, she teleported out of her suit, reappearing next to Luna behind the barrier, leaving the filly to fall back to the ground on her hooves. Everyone watched as the suit fell to the ground where it immediately began tearing at the seams as though by an invisible force. Pieces ripped apart and were cast aside like paper shreds. In little more than two minutes, the suit was a shredded mess beyond repair.
Dr. Mario could only watch, stupefied, at the display, before he was snapped back to reality when the snot merged together and began creeping across the floor towards him. He sprang into action, unscrewing the cap off his bottle and pouring a small handful of megavitamins into his palm. He carefully arranged them by color before dumping them onto the viruses. To his relief, the megavitamins still worked, quickly and effortlessly killing them; a part of him had grown worried the viruses were becoming strong enough to resist the megavitamins.
The filly locked a spiteful gaze onto him. When she spoke, it was with three different voices layered together: playful, snarky, and melancholy.
“You are quite the nuisance. What will it take for us to be rid of you for good?”
Dr. Mario primed some more megavitamins. “I’m-a never gonna back down,” he stated.
“How annoying.” The filly reared back and blew another glob of snot towards him. Dr. Mario dodged and proceeded to use the megavitamins on it just like before. The filly tsked. “You won’t win!”
She took off in a gallop, charging him in a little pink blur. He reacted on instinct yet again, jumping out of the way, landing on top of the barrier covering the pool. The filly charged him again, missing, but by a shorter distance this time. This couldn’t last forever; he needed to come up with a strategy to subdue the filly. Getting in close was extremely risky, and the princesses would have to leave themselves exposed in order to help.
He cast a brief glance their way while the filly was reorienting herself; they looked concerned and even a little upset, probably because they didn’t think they could be of any help in the fight. It was strange to think about; two all-powerful alicorns powerless against something as small as the Primary Virus, and he, a single human doctor, who couldn’t teleport or fly or use magic of any kind, only had his limited human strength to carry him through this fight. His biohazard suit had lost its purpose if the viruses were able to tear it apart, but it would at least protect him from a single hit.
A spark of an idea flitted through his mind. It was simple, yet dangerous, but it was all he had right now so he held onto it. He didn’t have much time to convince himself it was a bad idea as the filly charged again. This time, he held his ground, and the filly bit into the leg of his suit, pulling with all her might to tear it apart.
“Dr. Mario!” the princesses cried in unison.
The fabric on his suit was ripping surprisingly easily under the bite of a creature without canines, but then again, the viruses themselves were somehow able to rip it apart. He quickly bent down and hooked an arm around the filly’s body. He pulled with all his might while she struggled to break free. He set down his bottle to hook his other arm around her body. With the added strength, he managed to pull the filly off of him; a giant piece of his suit came off in her mouth which she spat out.
“Let us go!” she cried.
Dr. Mario moved fast. He removed one arm from her to reach down and pick up the bottle. The filly almost broke free of his grasp, but he held firm as he pressed the bottle up to her mouth. The filly’s eyes bulged at the sight of the megavitamins contained within and she shut her mouth, thrashing even harder in his grip.
“I could use-a some help!” he called to the princesses.
The princesses teleported from behind the barrier and next to him. Luna lit her horn and the filly’s body was enveloped in a blue nimbus and she stopped thrashing in his grip, allowing Dr. Mario to release his arm from her while keeping the bottle pressed against her mouth. The filly reared her head back, ready to blow another glob of snot, but was thwarted when Celestia erected a barrier covering the filly’s head sans mouth and the snot impacted the inside of it. Luna forced the filly’s mouth open and Dr. Mario carefully tipped her head back and gently dumped a fair amount of megavitamins into her mouth, her eyes filled with pure terror all the while. Once the megavitamins were in place, Luna forced the filly’s mouth shut. A moment passed and it was obvious the filly wasn’t making an attempt to swallow the megavitamins.
“Whoever you are, my little pony,” Celestia soothed, “you must still have a modicum of control over your actions. Please fight against the viruses’ influence and swallow the megavitamins. I believe in you.”
The filly’s eyebrows lowered in a show of defiance and she shook her head furiously.
“If she was asleep I could enter her dreams and perhaps give her the motivation to fight against them,” Luna remarked.
“If only we knew how the viruses are controlling her I might-a have some medicine to subdue them,” Dr. Mario said.
Celestia looked up in thought for a while, before saying, “I have an idea.”
She disappeared in a flash of light. In the minute she was gone, Dr. Mario’s mind ran with all kinds of fantastical possibilities as to what her solution could be. As such, it came as a surprise when she returned with nothing more than an ice pack.
“Set her down please,” she said.
Luna gently placed the filly face up on the floor while Dr. Mario kept the bottle over her mouth. Celestia placed the ice pack over the filly’s forehead while her eyes bulged with terror. She visibly tried to struggle under Luna’s magic, only for her body to relax a few seconds after the ice pack was applied and her eyes went blank. Luna released her magic hold, but the filly made no attempt to get back up, seemingly immobilized by the touch of the ice pack. Dr. Mario removed the bottle from her mouth, but she didn’t spit out the megavitamins.
He cast a confused glance at Celestia, to which she explained, “It was just a hunch, but keeping someone cool is how you relieve symptoms of a sickness, so it stood to reason that the viruses could be weakened by the same method. Truly, we are lucky that it worked.”
To think that a doctor could overlook such an elementary concept in the medical field of study— Dr. Mario could only laugh in response.
Celestia placed a wing over the filly’s body and began gently stroking her, “If you can understand me, my little pony, then please swallow the megavitamins. They’ll cure you, I promise.”
A glimmer of awareness came to the filly. She stared up at the three of them for a few minutes, blinking every now and then like she’d just come out of a trance. The genuine confusion in the filly’s eyes told Dr. Mario that the ice pack was working, that she was in control of her thoughts again. Then the filly seemed to realize she had something in her mouth and it shifted as she began building up saliva. A few moments later she visibly swallowed and let out a cute, relaxing breath.
“Feeling better?” Dr. Mario asked.
The filly met his gaze and arched her eyebrows. “What are you?” she asked very weakly.
“Imm’a Dr. Mario!” he introduced himself. “And I’m a human!”
“What is your name, little one?” Luna asked the filly.
“Melon Seed,” she replied. “Where’s my daddy?”
“He is safe, rest assured.”
“I don’t remember anything.” Melon Seed swept her gaze around the reservoir chamber. “What is this place?”
“We’ll explain everything later— to all of Canterlot, we promise,” Celestia said. She cut off her barrier and lifted Melon up in her magic. “For now, we need to get you quarantined and treat your injuries.”
“What does ‘quorein— quaireent—’ what does that mean?” Melon asked. “Is it painful?”
The adults all shared a laugh.
“Don’t worry, it isn’t,” Dr. Mario assured her.