<CLANG>

“Be honest with us, Doc.”

<CLANG>

“How bucked are we?”

<CLANG>

“…Doctor?”

<CLANG>

He would’ve said something cheeky in response. Perhaps something within the lines of ‘Language, Ditzy. But yes, we’re pretty bucked.’
However, he didn’t hear her.

<CLANG>

He realized that he no longer had time to allow his now third guest in his head to settle in his own calm, safe, enclosed little corner, and would need to handle a crash course instead. That was, if he intended on opening his eyes to analyze whatever threat they were faced with at the time.

<CLANG>

When he opened his eyes, he felt like he was suffocating. That’s how heavily the darkness had hit him.

All the regrets and tears the caretaker had never been able to truly bring on the outside. All of her grudges, her spites and remorses. Every single dissatisfaction that had ever weighed down on her was rushing over him.

He had no small share of personal demons himself, which he had grown accustomed to, to an extent. It wouldn’t have taken him long at all to sort through these new shadows, if only he had the chance. However, thus was not meant to be. He wasn’t allowed to rationalize any of the new emotions invading his mind, and he was risking to lose himself.

He opened his eyes in order to be able to see the problem he was faced with, but in doing so he lost his ability to think at all.

“…Doctor?”

He could no longer hear her. The whole world had gone silent.

As far as he knew, there was nothing left in the world but the beast that was threatening him and all that he held dear, though he could no longer recall what those things were. All he knew was the indignation, and unending fury that he’d kept subsided ever since the Last Great Time War.

If he were to try to pry even an inch of attention away, he wouldn’t have noticed the tears suddenly pouring out of Ditzy’s eyes, or the look of sheer terror on the others’ faces, or the deafening clangs against the faltering shield. The first thing he might’ve been able to notice would be the whispers inside his head, as Nightmare had had enough time to figure out a way to finally take root in his mind. Should the shadow not have secured so much of his mind already, the Doctor would’ve noticed the thoughts of reason and care being extinguished before they even formed, and the never-ending, accelerated, accentuated thoughts of self-righteous violence flooding through instead.

There used to be a shield in his path. The Doctor had found strength in both his new body, as well as its magical affinity, enhanced by none other than the one person he was directing his anger towards.

The shield shattered.

There was a terrible warcry, a promise for blood and gore the likes of which ponykind hasn’t heard since times forgotten and erased. Ditzy couldn’t believe her senses when she finally came to realize that such a terrible sound could come out of the Doctor. At the same time, an ungodly shriek of pain and panic escaped the second monster. The pickaxe fell to the ground, soon to melt away into the same black sludge composing the beast’s integrity.

Before long, the Doctor had reached the heart and forcibly stolen the tar and misery for himself.

Then he ran off, leaving on the ground an unconscious white mare with red and black stripes in her long, subdued hair. And another, crying for not being able to prevent this from happening.

Ditzy and the others would watch on as the fallen Time Lord left their line of view, unaware of the multitude of eyes staring back at them from all other directions.

Nightmare did not anticipate any of these events to transpire the way they did.

If he had a hand, or a forehoof of his own, he’d rub the latter trying to better understand the situation. Instead, he opted to have Twilight do it for him, from the folds of the Castle of the Royal Sisters.

He didn’t have the audacity to have Twilight seat herself on the single throne in Luna's tower. Power never was his ambition, so he never saw any allure to the act. Instead, he allowed his mind to wander aimlessly as he searched through the cold stone walls, recalling what it was like, before things went out of hand.

He wondered if Twilight could see what he saw through her eyes. The once majestic ballrooms and courts, now only rubble and ruin.

Eventually, they seated themselves at a balcony doorway, in Luna’s old chambers. The balcony itself long since broken and fallen by the elements. After a thousand years of wind and rain, not to mention what might’ve happened that fateful eclipse, he was surprised that even this much still stood.

The duo sat there for hours, still. Unmoving. Twilight had been changed here in appearance. Her black fur only ever shifted in its own wind, her white eyes studying the distance.

Yes, Nightmare assumed they were quite well acquainted by now. After all, he was using her mind to store his own memories, both sorrowful and fond. At least, what little of them remained.

He wondered, though. If he were to allow the student under his control to wander with her own mind, would she remember? What she was seeing now? What drove him, what kept him going? Or would she forget immediately, like her friends had so far?

He had intended to take advantage of the Doctor’s moment of emotional vulnerability by using the anger sprung from seeing what had been done to Pinkie Pie. He only managed to render the strange interloper into a state of tunnel vision, drawn out by both rage the likes of which he himself hadn’t known since he merged with Luna; as well as simply, being tired.

Tired of caring. Tired of trying to reason with others. It would seem that the Doctor had quite a few shadows in his own past.

So far, Nightmare had only scratched at the Time Lord’s boundless mind. With the sudden influx of power from Pinkie Pie, he only barely managed to secure his influence. He needed it, since by no longer having an immediate target to his rage, the Doctor risked coming to his senses. Luckily it appeared that he had no real desire to remain in place to begin with.

The fallen lord of time's anger quickly got joined by his sorrow and shame. They bolstered the shade’s power barely enough to nudge him to continue his warpath. To continue opposing him.

At least this way Night could try to somewhat predict and control the Doctor’s actions.

It seemed very unlikely at this point, but he might even be able to succeed in gaining the Doctor as an ally before the day was over. That was, as long as he didn’t risk becoming vulnerable to the Elements of Harmony in the process.
He was not certain what he might do, should it come to the point where he would have to choose between the Doctor and Twilight.

“I suppose it cannot be helped,” the duo sighed in unison. “At least we’re about to retrieve three of them now, plus two more.”

He shifted his consciousness towards the area where the Doctor had just left. Nightmare ordered the animals previously under Fluttershy’s dominion to retrieve their caretaker, and the others.

He was no longer phased when he noticed that things hadn’t gone according to plan. Again. Even if this certain instance seemed rather… unusual.

Fluttershy had a way with animals. Whoever had ever met the mare knew this much well enough.

It was quite possible that there might've been a magical origin to this phenomenon, though unfortunately, as is with all things magical in nature, it was unclear at best, and utterly impossible to compose an adequate question at worst.

It’s… relatively safe to assume that the caretaker’s abilities were by no means natural. Ponies are actually mostly unnatural. They don't just rely on their magic, they are magic as well. Some of them ever more than usual... which is one way of explaining Pinkie as a whole. She's as much part magic as she was part darkness in her Tar Ogre form.

So there they were. Ditzy was leaking from the eyes despite repeated wiping and Applejack was trying to shake Pinkie Pie awake when suddenly, Big Mac brought their attention to what was going on in their surroundings. They’ve found the entire area swamped with beasts of varying size and sharpness. Every single one sporting the same vacant expression on their face, aside from the butterflies embedded on their faces like some kind of evil childish face paint.

Noticing that they had no chance of fighting them all, the group of would-be heroes decided they should try to run away. So Applejack threw the downed party mare over her back and called for her brother to make a path.

No such luck.

He was big, he managed to send a cragadile and woolymong flying over the crowd, but the natural predators were better at waiting for an opening. The manticore had pinned him down, stared at him and growled deafeningly in his face like the farmer owed it money, until Fluttershy finally decided to make herself noticed.

And boy, did she offer them all a scolding…

“I have never met anyone acting this way! I’ve dealt with some temperamental critters in my life, but I’ve NEVER met someone trying to hurt someone else just because they’ve been told to do it! You’re not even hungry, you’re not even angry at us! You’re just doing this because you don’t want to upset a bully?! What kind of a lion are you?!”

A large bramblesnake (like a rattlesnake, only made out of brambles) decided to try to sneak up on her while she was distracted. It was not meant to be.

“And just what do you think YOU'RE doing, mister?!”

The snake coiled back and gulped under her unrelenting stare.

“What, you think that just because you’re bigger and stronger than us, you’re allowed to just do what you please?”

“Well…”

“Well what? You think you get to find an excuse? After what you’re all been trying to do?!”

Deep down inside, they’re all just little kids. Aren’t we all…

They grouped up, instinctively, trying to find some security in numbers. It didn’t help. The angry lady wasn’t done with them.

“You were going to hurt us, for no reason but because that selfish meanie wants us to serve him too! Well I’m sorry, but I’m not going back to being his plaything, and none of you should stand for it either!...”

“Should we do somethin’?” whispered Big Mac to his sister.

“Ah think Flutters’ got it covered.”

“Ah wasn’t worried about her…”

“…of yourselves! You’re not willing to stand up to him, but you’re more than willing to pick on innocent ponies that only want to get their friends back! I only hope your mothers don’t find out about what you’ve been up to, because I’m sure they’d want to bury their faces in embarrassment!”

All of the animals were now hanging their heads low, some of them pawing at the dirt in shame, the face paint long since erased.

“…Point taken.” whispered the apple sibling back.

“Now, I want to hear some apologies.”

Grunting, hissing, mewing and bleating all sounded in unison, extremely half-heartedly. “Sorry…”

“I didn’t hear you!”

They repeated themselves louder, as requested. “We’re very sorry, ma’am.”

“That’s better. Now I want you all to go back home and keep out of trouble from now on. Make sure you don’t get mixed up with baddies like Nightmare.”

“Yes, ma’am.”

They all turned tail and left their own separate ways. At the same time, it appeared Nightmare had decided that it was over, and allowed the area to finally turn back to normal.

Fluttershy let out a sigh in frustration and turned back towards her friends, searching where Ditzy was beside Pinkie Pie.

“How is she?” the caretaker asked the mailmare.

“I don’t know. She’s resting, and her mane and fur started to turn back to normal, so I suppose that’s a plus.”

Ditzy didn’t look very well either. She managed to stop crying, and decided she didn’t have time to wallow in heartache at the moment.

“Are you okay?” Asked the caretaker, laying a hoof over hers.

“No, not really. But I will be as soon as we stop Nightmare and get the Doctor and the others back.”

It wouldn’t have been hard for him to bring Pinkie back without resorting to violence. The tar surrounding her was self-replenishing, but if he just stopped to think for a moment, he might’ve been able to remember what he said to himself inside Applejack’s head. That maybe it was susceptible to light.

He had a flashlight handy. He also had the necessary tools to enhance the power output of said flashlight as much as he might ever need. Maybe Pinkie would’ve fought back. Maybe him, Big Mac, Applejack, or even Ditzy of Fluttershy would’ve gotten hurt. Maybe even badly, by that pickaxe…

No. As long as there was at least a fragment of the friendly, loving, selfless party pony left inside, no such thing would’ve ever come to pass.

Things could’ve most certainly gone better. However, they didn’t.

It wouldn’t have been out of the question to assume that the Doctor would fight back. However, it just so happened that at that single point in time, he had finally found his match. He himself had finally caught the short end of the deal that had been dealt to every single one of his adversaries so far.

Every single time, they would be caught either off-guard, surprised, or even out-smarted by the Doctor. This time, however, he found someone that would get under his skin, and for once, use the chance to drive for goal.

No more companions sacrificing themselves so he could be saved.

No more gloating, or stalling, or distracting.

No more slipping away through trap-doors, deadlocks, wolfsbane or teleporters.

This time, he was the one to pay. This time, he was the one who would get to be analyzed, dissected, watched for an opening. The Time Lord was still far from converted, but Nightmare was as patient and unrelenting as the darkness inside any, and every, nook and cranny.

The Doctor would need to pull a very impressive hat trick to tip the scales back in his favor.

Nightmare's influence had been bolstered when the Doctor had relieved Pinkie of her suffering. The shade was certain that all of that darkness would’ve been more than enough. However it would seem that he was wrong. The Doctor was far more resilient that he would deem conceivable.

The Time Lord’s pelt and mane had been completely overrun by the tar, but it all subdued and vanished with nary a problem. He was much stronger willed than Nightmare would’ve ever dared to imagine. The shade decided it would be in his best interest to focus on this interloper as much as he could.

The Doctor was not an average foe, but he was not invulnerable. His hair and coat presented a reddish tint now. The whites of his eyes turned completely black. There was the persistent presence of his irises. The blue circles in the now concentrating black which was now threatening to swallow them regardless.

The Doctor refused to give in, but he wasn’t gaining any ground either.

As it seemed, this stalemate wouldn’t last. He was headed towards his next target, where it was very likely that he'd lose himself.

Nightmare had nothing to do now but think. Think of what was to come, what needed to happen, and what would most likely happen instead. Twilight's intelect offered him quite the edge, making her the obvious choice for a strategist and main host. Even so, there were so many variables. The odds were even, from this point on, it could go either way.

It was difficult for him to recall many things, however, so he relied mostly on Twilight's knowledge and strategic mind. When he would try to search through his own memories, it was like trying to make sense of what was left of a burned book. Yet he knew more than enough. He managed to save the most important parts.

It wasn't like he wanted things to go the way they did. Violence was never in his kind's nature. He was actually a peaceful race. They had never harmed anyone else throughout the millennia.

...Not intentionally, at any rate.

Even so, he had always found himself... different. Where his peers would be content with eternity watching from the shadows, doing nothing but observe, he felt... out of place.

It was only later when he'd found out that the feeling he had was loneliness. A feeling which drew him to someone else sharing his grief.

How does it feel, to drift through shadows and dreams for years at an end without meeting another one of your peers, but when you would all conglomerate during processions(*) and ceremonies(**), you would feel even more alone than you've ever felt throughout all of those solitary years combined?
How does it feel, to find yourself attending a ball supposedly dedicated to both princesses, but feeling only love for your sister? Like you weren't even there? It was more than just being ignored. She was not just being overshadowed. The whole thing was nothing but a sham.

He eventually grew to hate the dark.
She eventually grew to hate the light.

It was only by chance that he came across her one day, after finding the most radiant being he'd only seen memories and dreams about.
It was just another night. Alone. Everyone else either asleep or on night shifts. Every single pony who had finally finished their rounds of the night saying a single common thing upon arriving home. That they were so happy to be able to sleep.

He found her on a balcony. Alone. Upset. Yet... alone, in the dark. Like himself.
"What is the matter?"

Author's Notes:

The title is a quote from the Joker. In case it wasn't obvious enough.

(*) You don't want to know.
(**) You REALLY don't want to know.
Different cultures and all that. It's pretty damn disturbing.

Remember that one chapter, where the Doctor met Fluttershy and almost traumatized her by looking a little too closely into her eyes? Eyes are the window to the soul, pony magic is directly linked to their moods, ponies constitute around 60% magic, bla bla bla. I could go down this line of explanation to explain why Fluttershy's stare is plausible, but I don't feel like it. It's magic. End of conversation.

Doc regained some of his senses when his rage died down, and before you go on saying that someone as Marty Stu as him would never let himself be controlled like that...
BURN WITH ME, MARTHA!
...I'm actually going to go a little more into detail regarding his current predicament in the next chapter.

Pinkie took a lot less time than the other ones... <stares at the two chapters Applejack took>
I'm not apologizing. How much it took, it took. I'm not lengthening it. I'm-
<Adds Nightmare's explanation in the end>
DAMNIT!

Oh well... I've linked a video at the end of the chapter. I hold no rights over it, or the comic which it interpreted. I solemnly declare that I find both authors infinitely awesome and sexy and whatever and that I'm not making any money off of stealing their shit or linking to them.

Also, it would appear that I'm modifying a few details. For one thing, Nightmare isn't as alone and ambiguous here. He's part of a race (like a certain draconequus), which I'll go into detail at some point in the future which I've yet to decide.