While the train was all well and good for getting around Equestria, for sheer speed and convenience, nothing beat flying. And so it was that that's how Twilight now found herself travelling, soaring through the skies of Equestria as fast as her newly-made wings could carry her, a look of determination plastered all over her face. Never mind how much it ached to have constant wind blowing in her eyes, she did not flinch from her travels, straying only to look behind her, where she saw her adopted son, Spike, holding onto her mane, sitting atop a pair of saddle-bags she carried upon her back. Spike was nervous about being up so high, which wasn't unreasonable, but even so, he gave his mother a reassuring smile, leading to her looking forward once more. It had only been mere days since her return from the human world, and now, she found herself needed once more in her home; Ponyville. Within moments, that home soon came into view, and she upped the pace, flapping her wings harder than before. In only a minute, the town, after having grown closer and closer, was finally within reach for a landing. So, assuming her landing stance with her wings, she slowed down considerably, before, at long last, touching the ground with her hooves. Letting out a sigh at this fine landing, she turned to see Spike hopping off her, after which she looked around to smile upon the sight of her home.

However, that smile faded soon afterwards. For she then saw just how bad things were here. Colts, fillies, mares and stallions alike, were all sitting around in various places, from the nearby public bench, to in the doorways of their homes, to even out in the middle of the street. They didn't seem sick, just tired, as if they hadn't had a good night's sleep for weeks. Others did not seem to be affected by this, and were rushing about in an attempt to help their neighbours and friends. Gaining a look of immense concern over this, Twilight looked to her saddle-bags, after which she lit up her horn and levitated a small piece of parchment out of it. Hovering it in front of her face, she began to read. The message had been from Fluttershy, which in itself was a surprise, but the words were nevertheless clear. They needed her back in Ponyville to sort out some kind of problem. And, just from looking around at the other ponies around her, it was obvious why they thought they needed help with this. Narrowing her eyes a little, Twilight placed the parchment back into her bags, before then striding off with all haste in the direction of her home; the Golden Oak Library. Spike followed her close behind, and together, the two made their way through the town, looking upon all of the ponies and animals that displayed this rampant lethargic streak to them.

It wasn't long before the library came into view, and there, to Twilight's surprise, she saw that Rainbow Dash was standing in front of the place. The cyan pegasus was scouring the area, most likely looking for her. After a few seconds later, she noticed the young alicorn and dragon approaching, and after breaking out into a smile, she turned and knocked upon the library's front door. Almost instantly, it opened, and Twilight’s other friends, Pinkie Pie, Rarity, Applejack and Fluttershy, all exited the building, earing looks of great relief to one degree or another. Although Twilight was overjoyed to see her friends again, she knew there was no time to waste, as she then gestured to the inside of the library. Nodding, the other mares soon entered the place once more, with Twilight following soon afterwards. After closing the door behind her, and handing Spike her bags, Twilight turned towards her friends. Although she would have wanted nothing more than to simply embrace those five mares after being away from them for so long, it was clear from the looks on their faces, most notably Fluttershy's and Applejacks, that things weren't entirely happy with them. The sting of their last meeting was still there it seemed, and so, Twilight cleared her throat, instead electing to keep things to the most important issue at hoof.

"How long has this been going on?"

Rainbow let out a sigh before answering her.

"A couple of days. At first, it was just animals, like our pets, but then..."

She didn't finish, for Pinkie Pie, in her usual manner, soon interrupted her in an enthusiastic manner.

"But then everypony started going all limp! Like all the energy just...just left them!"

Twilight nodded at that, thinking hard on the matter. Despite all of her knowledge of the future, this epidemic didn't seem to be all that familiar. Having ponies go so without life like this was somewhat reminiscent of the effect that Tirek's magic-stealing abilities had, but the ponies in town all still had their cutie marks, so it couldn't be him, even if he had somehow managed to escape the prison Twilight put him in. It could be a spell of some sort, but she was unfamiliar with any other magic that could do such a thing. This whole thing felt like some kind of plague, and yet everypony seemed perfectly healthy, just with a complete lack of drive to want to do or say anything. It was confusing to say the last, and soon, Twilight found herself staring into the eyes of Applejack, who had silently walked up to her as she thought about this.

"Any of that fancy future stuff helpin here, Twilight?"

The words had been emphasised with a gentle poke to Twilight's forehead by Applejack's hoof, but Twilight nevertheless just shook her head.

"I'm...I'm sorry. I don't remember any of this."

Rarity turned to her with both confusion and shock on her face.

"But...you have knowledge of centuries ahead of our time! How can you not know about this?"

Twilight shook her head.

"I...I just don't! I never encountered anything like this in the first time line. This...I don't know what this is!"

To say that her friends looked disappointed in her would have been an understatement, as all of them hung their heads somewhat after hearing that declaration. Shame was all Twilight felt in this moment. If she didn't know what was wrong, she wouldn't be able to help, and helping was her goal in life now, her assigned penance. Needless to say, this was a ratter down moment for all of them. However, Twilight found that she hadn't the time to dwell on it, for she soon heard her son speaking up, gaining her attention.

"Er...Mom? I think you need to look at this."

Turning, Twilight's eyes widened with shock as she saw what the young dragon was speaking about. There, in his clawed hands, was her crown, the Element of magic. She had brought it back with her from the Crystal Empire after having used it up there, but now, something seemed to be happening with it. The star-shaped jewel at its top was flickering, like a light about to run out of power. Immediately, Twilight used her magic to levitate it over, staring hard at the thing in concern. Not since the corruption she herself had inflicted upon it had anything ever seemed wrong with the Element, and it was not long ago that such darkness had finally been driven from it. To have something occur to it now was not something the young alicorn wanted in the slightest. However, as she looked upon it, a new idea began to make itself known in her mind, and realisation soon followed. She didn't know how, but that was now the only answer she could think of, and so she spun around, looking at her friends as she spoke in a hushed tone.

"The tree...the Tree of Harmony?!"

As one might expect, this caused a number of confused glances amongst the assembled mares, until eventually, Rainbow approached her lavender friend to say what was on all of their minds.

"Er...the what?"

Twilight let out a sigh. She had hoped that this particular chapter of her life could have been avoided, given all the work she put into making Equestria safe. And yet, it still managed to come around. So, steeling herself, she began to explain things.

"The Tree of Harmony. The source of all balance in the world. Over a thousand years ago, it was from that tree that Princess Celestia and Princess Luna first took the Elements of Harmony, to use in their battle against Discord."

All of the mares, even Applejack and Fluttershy, stared at her, clearly enraptured by this tale, which prompted Twilight to continue.

"In the original timeline, Discord planted a group of malicious plants, known as plundervines, to attack Equestria at a later date after his imprisonment, primarily with the goal of...well...killing the tree. I guess he hoped that doing that would help him be free later on."

Rainbow narrowed her eyes at that.

"So...those vine things are what's causing all this?"

Twilight shook her head before answering.

"That can't be. When I was journeying across Equestria all those months ago, one of my main goals was to hunt down and destroy every single one of the plundervine seeds. I accomplished that goal, so it can't be them. So..."

Gradually, Twilight's expression became one of worry, as she turned away from the other mares.

"...maybe...maybe the tree was dying anyway. Maybe the vines just helped things along in the first timeline, and that it was doomed from the start even without them."

Silence fell after those words, as none of the other mares dared speak up, lest Twilight have something important to say soon afterwards. It seemed their instincts were correct on this count, as she soon narrowed her eyes before turning to look at them once more.

"If the tree is indeed failing...then that is why everypony is acting the way they are. All of us are connected to it. We are creatures of balance, and it is the source of all balance. If it falls...so do we."

As expected, those words sent looks of shock all around the room, prompting all of the mares to look to each other with concern. All, that is, except for Rainbow, who took a step forward with confusion upon her face.

"So...if that's true...why aren't any of US affected by this?"

On that note, Twilight had a clear answer in mind.

"Best guess...our use of the Elements over the years has allowed some of the tree's inherent power to rub off on us. That probably means the six of us are effectively shielded from whatever's been happening to everypony else."

Rainbow thought on that and nodded, apparently agreeing with that theory. Not long afterwards, the cyan pegasus gained a look of determination.

"So...we fix the tree. How do we do that?"

Twilight smiled, happy at seeing the loyalty her friend still had for her, even if she was the only one to feel that way so far. However, before she could open her mouth to speak, she found herself distracted by a sound coming from behind her. Turning, she gained a look of great shock as she saw, to her horror, that Spike now tumbled, falling to his knees before gaining a look of extreme tiredness. Immediately, his mother rushed to his side, as did all of the other mares, and the former soon found herself lifting the young dragon into her hooves, keeping him close as she looked to him.

"Spike! Wha...what's wrong?"

The young dragon, still having at least some energy left, shook his head somewhat.

"I...I just kinda feel tired, that's all."

Fear gripped Twilight's heart, as there was no doubt in her mind that the fall of the tree was behind this. She looked to her friends, each of whom seemed to be concerned for the young dragon, though obviously not to the same extent as she was. However, it wasn't long after that when Twilight heard yet another sound, and turned her head to find that Trixie, her student, was now coming down the stairs. Although the former show-mare was, at first, surprised to see her mentor back home, that surprise soon turned to worry when she caught sight of Spike, which led to her rushing down to join the group. No words passed between her and Twilight, but the look that the latter was giving the former was nevertheless loud and clear; look after my son. Trixie nodded at that, and moving as carefully as possible, took the young dragon from Twilight, with the young alicorn never taking her eyes off him as Trixie set him down ion a nearby sofa. The other mares watched this happen, before then turning to Twilight, whose expression slowly morphed to one of fierce determination. She turned, looking upon all of them, before speaking in a stern manner.

"Girls...gather your Elements and bring them here."

They looked to each other with confusion, before looking to Twilight, at which point, Fluttershy, for the first time in all of this, spoke to her.

"But...what are we going to do?"

Twilight narrowed her eyes as she turned, looking out of the window in the direction she knew the tree was in.

"We're going...to give the Elements back to their owner."