Everypony recalls the tale in Equestria about the two human boys with the powers of light and dark, who joined forces with those of harmony to defeat the tyrannical Serpent King. What nopony knew was that the moment the boys returned to their world, they had brought with them one of the greatest of evils in Equestria. And now a new adventure begins for the ponies that brought harmony to Equestria and the human boys who saved it.
Last time, three months had passed since the threat of the Serpentine and the Serpent King had been vanquished. Inside Golden Oaks Library, Twilight Sparkle was studying with Spike assisting her. Suddenly Spike belched up a scroll, "A letter from Princess Celestia?" Twilight gasped, as she used her magic to unravel it and read its contents.
"My dear Twilight, something terrible has happened and I need you along with the girls, Wildcard, and Muse to come to Canterlot straight away. Time is of the essence." Celestia's voice echoed in Twilight's thoughts as she read it and gasped.
"What's it say, Twilight?" Spike asked, as he got back on his feet.
Twilight was surprised and concerned, "Spike, we need to round everypony up." She ordered.
"What's wrong?" Spike asked in concern.
"Princess Celestia says there's a matter of great importance that requires our attention. Come on!" she ordered, as Spike got on her back, and she galloped out of the library determined to find her friends.
Meanwhile in the park, Rainbow Dash was behind a bush, spying on another one of Muse's and Wildcard's dates, "Come on kiss…" she said to herself, as the two were leaning closer and closer until…
"Muse! Wildcard!" Twilight called, as she galloped over to the two, thus breaking up their moment.
Rainbow reached out to the side, grabbing a paper bag and screamed into it, "WHY?!" she asked herself in frustration.
"What's up, Twilight?" Wild asked.
"I just got a letter from Princess Celestia. She wants us all in Canterlot right away." The alicorn explained.
"Gotcha. You hear that, Rainbow?" Muse asked, as she and Wild glanced at the bush, as the pegasus popped out from it while looking sheepish.
"Come on we gotta get the others." Twilight ordered, as they hurried to round up Rarity, Pinkie Pie, Applejack, and Fluttershy.
Once they were rounded up, they caught a train ride to Canterlot, "What did the princess say this was all about?" Muse asked curiously.
"She just said something terrible has happened and time is of the essence." Twilight answered, while feeling worried.
"What could've happened? I mean after the Serpentine were defeated, Ponyville and Equestria's had nothing but peace." Wild explained in wonder.
"Well there's always something new that comes up." Twilight replied, having been thorough this ordeal too many times.
"And they always turn out to be scarier than the last problem." Fluttershy quivered.
"Whatever it is I'm sure we can handle it." Rainbow brushed it off like it was nothing.
Soon enough, the group arrived in Canterlot, and was on their way to the castle, "I hope we're not too late," Twilight said in worry. They arrived at the castle and entered. They went to the throne room to see Princess Celestia, Princess Luna, and Princess Cadence awaiting them, "Princess Celestia, Princess Luna, Cadence!" Twilight called.
"Twilight!" Cadence giggled as the two met.
Sunshine, sunshine,
ladybugs awake!
Clap your hooves
and do a little shake!
The two laughed, as Celestia and Luna approached. Celestia spoke up, "Thank goodness you all made it here."
"We have important matters to discuss with you." Luna added.
"What's going on?" Rainbow asked.
"I'm afraid we have terrible news." Cadence began in worry.
"Terrible how?" Applejack asked in confusion.
"Terrible as in 'the end of life as we know it', but it's not for Equestria just yet." Celestia explained, which got the eight ponies and dragon confused.
Luna explained things clearer, "You all remember how Pythor and the other generals used the Orochi Sword to become the five headed Serpent King?"
"Yeah, with our elements of harmony, and Dustin and Alistair's powers we took that snake down like nothing." Rainbow answered with pride.
"And Zyphon sent all that remained of the snake flying halfway across Equestria!" Pinkie cheered.
"Yes we know that," Celestia replied, wanting getting back to the matter, "But there was more that went on that day."
"More that went on?" Twilight asked in curiosity.
"What do you mean?" Spike asked.
Cadence spoke up, "As it turns out with the Serpentine running amok along with the appearance of the generals and their final form, many ponies released an enormous amount of fear and terror that had not been seen for many years."
"The amount of fear that was released from them awakened something we thought was gone." Celestia added.
The group was confused, until Luna spoke, "Ebon has returned."
The ponies turned shocked, as Fluttershy spoke, "Ebon? As in the dark unicorn who was said to have been defeated by the five unicorns?"
"The very same." Celestia confirmed with a nod.
"How's that possible?" Wild asked in shock.
Luna continued, "We discovered that the five unicorns didn't entirely defeated Ebon. Merely they destroyed his body, while his essence remained dormant in the earth."
Cadence took it from there, "The fear and terror released by the residents of Ponyville and those caught in the middle of the serpents rampage was just enough energy to feed Ebon's spirit to get strong enough to rise up out of the earth."
"So he's free?" Twilight gasped in shock.
"I'm afraid so," Celestia answered, with worry as well, "But he is not in Equestria."
"Not in Equestria?" Applejack asked in confusion, "Where else could he be then?"
Celestia answered, "He's gone to the human world."
The ponies eyes widened in horror, "THE HUMAN WORLD?!"
"How's that possible?" Twilight asked, in confusion, "There's no way he could've gotten there by himself."
"You're right, he didn't," Luna began as she and her sister started looking remorseful, "Because my sister and I helped him get there."
"Helped him, how?" Pinkie asked.
"When we opened the portal to send Dustin, Zyphon, and Alistair back to their world, we did not realize that Ebon's essence latched onto Alistair providing himself a vessel and camouflage from our magic." Luna continued.
"So Alistair had no idea he was taking Ebon back to their world?" Muse asked, hoping she got all of the details correct.
"I'm afraid he didn't." Celestia answered.
"Oh great, one of the oldest of evils in Equestria is loose in their world?" Wild asked in shock.
"So what can we do?" Twilight asked.
"The only thing we can do is open the portal we used to send the boys home, and you must go there yourselves to find Ebon and defeat him." Luna instructed.
Wild spoke up, "And did you summon us here just so we could hear their mission?" he asked on behalf of himself and Muse.
"Actually we've decided to send you two with them," Celestia began surprising the eight ponies and Spike, "While you do not have power like the elements of harmony, you have proven to be worthy allies since the Serpentine incident," she then thought to herself, 'And perhaps Twilight can find more answers as to how they were able to use magic when they fought them.'
"Princess, we accept the mission." Twilight answered, as the six were given their respective elements, which Twilight tucked away in her bag.
"Keep your elements close to you," Celestia instructed, "Your best chance is to find Dustin and Alistair and warn them of the situation if they have not already become aware of it."
"And remember my little ponies," Luna added, "This human world is by far ultimately different from ours. Just as Dustin and Alistair had to adapt to living in Equestria, you will also have to learn how to coexist with humans as best as you can." The ponies and Spike nodded.
Celestia and Luna used their combined magic to open the portal like before. The ponies stood before it as Twilight spoke, "Ok this is it." Twilight said, as he entered with Spike.
"Wait for me!" Pinkie cried as she jumped in.
"Leap of faith!" Wild jumped in.
"Let's go!" Applejack called, as she and Rainbow entered.
"Oh I hope this world travel doesn't damage my look." Rarity feared.
"Worry about that later." Muse said, before nudging her into the portal, "Come on, Fluttershy."
"Ok, I'm coming." Fluttershy said meekly, as she and Muse entered before the portal closed.
"Do you really think Twilight and the others will survive in this other world, Princess?" Cadence asked Celestia.
"I too have my doubts and worries about this, sister." Luna voiced up as well.
"We must have faith in them as we've done so before." Celestia encouraged her fellow princesses who nodded in agreement.
Meanwhile, the group was flying through a vortex until they were heading for a bright light, "Head towards the light!" Pinkie called in a mystic tone.
"What like we have a choice?" Rainbow asked in sarcasm, as they were engulfed in the light at the end.