Sure enough, the very next day, Celestia and Luna called Cadence and Shining Armor to Canterlot. It didn't take long for Princess Celestia to reveal what they had been called in for. "Have you ever heard of Lord Tirek?" Celestia asked the two.
"No, never." Was the response.
Celestia sighed. "I expected such a response from you two. Alas, I'm afraid it has become necessary to explain his history. I feared this day might come, and part of me hoped it never would," She pulled out a massive book, and opened it up. The pictures displayed two strange creatures, as Celestia narrated. "The story of Tirek dates back to over 1,000 years ago, a time shortly after Luna and I had ascended to the throne. Tirek, and his brother Scorpan, came to Equestria from a distant land, with the intent of stealing Equestrian magic. Some claimed they needed it to discover 'The Rainbow of Darkness', but there is no evidence such a thing existed outside of fairy tales."
"Oh yeah, I remember those," Shining commented. "When I was just a little colt my mother was fond of telling me stories involving her and these ponies she once knew. Stories involving them and a strange bipedal creature called Meghan. One of the ones she was most fond of telling, was the one about how her and the five ponies, alongside Meghan, defeated Tirek in his Castle Midnight. And I believe The Rainbow of Darkness came up often."
Luna spoke next, as she flipped the book to the next page. "Well, Tirek and Scorpan certainly aren't fairy tales, they were real. However, Scorpan soon discovered that the ponies of Equestria were peaceful creatures, and not the savage brutes his brother had led him to believe. Thus, he befriended them, even gaining the trust of our beloved mentor, Starswirl The Bearded."
"Guess even Starswirl had a few beings he could consider friends," Cadence interrupted. "Sure wish I'd have known about that when I was foalsitting Twilight and trying to teach her about the importance of friendship."
Luna cleared her throat as the book was flipped to the next page, now depicting Tirek and Scorpan on their own in what appeared to be a cave of some kind. "Having befriended the ponies, Scorpan urged his brother to abandon his quest and renounce his pony hating ways. But alas, Tirek refused to oblige."
The book was flipped to the next page, which now showed Scorpan meeting with Celestia and Luna. Celestia narrated in a much more somber tone. "Unable to convince his brother, Scorpan came to us for help. He told us of Tirek's intentions, but could not bring himself to fight his own brother. Fortunately, he had no need. Our magical powers combined proved to be more than enough to stop Tirek. But rather than destroy him, we had him banished to Tartarus for his crimes. And Scorpan returned to his own land, never to be seen or heard from again as far as we know."
"However, Tirek has now escaped Tartarus!" Luna said dramatically. "We suspect it must've happened just over a year ago, when Cerberus left his post at the gates and wandered into Ponyville. A quick head count the following day revealed one prisoner missing, and Tirek was that missing prisoner."
"But, if he's really been on the loose for so long, why has he waited until now to strike?" Shining Armor asked, wondering if perhaps the princesses were hiding something from him. "If he harbors so much of a grudge against Equestria, why keep a low profile for over a year? It makes no sense."
"I think I can explain," Celestia replied, and stood up from her spot at the table. "When Tirek was banished to Tartarus, we made sure to strip him of his magical powers. Unfortunately, it was not permanent, we relied on the demonic abilities of Tartarus to surpress Tirek's abilities when they did return. After all that time spent trapped in Tartarus, Tirek was left very weak. I suspect it is only now that he has managed to regain his dark powers, strong enough to drain the magic of unsuspecting unicorns."
"And I think I know just the pony who can stop him." Cadence smiled, as she eyed Shining. It didn't take a genius to figure out who she was referring to.
"Me? Cadence, I'm flattered you think so highly of me, really I am," Shining modestly blushed, while scratching the back of his head with a hoof. "But, I don't even know where Tirek might be, let alone how I'm supposed to stop him if I DO find him."
"You took the words right out of my mouth, Shining Armor," Celestia said, and then paused and drew a deep breath before she added in a very serious tone. "Which is why I'm afraid I must call in another to stop Tirek. Discord!"
"What?!" Shining Armor and Cadence both gasped.
"Your reaction is the same as mine when I first learned of it," Luna commented to the two. "Even now I am still not sure if sending Discord is truly the best option here. He may be reformed, but he's still very much a wild card at this point. We don't know for sure if he will be loyal to us."
"Believe me, those were all concerns I asked myself before I decided on Discord," Celestia explained. "And it's not a decision I came to easily. But that is part of the reason why I had him reformed in the first place, this is the purpose for which his magic will be of good use to us. Unfortunately, I must send him in alone. To send someone with him, even a non-unicorn, is too risky. Even though he's not back at full power, Tirek is not a threat to be taken lightly. I fear he may hurt or even kill anyone if he believes it will help him achieve his goals."
"But why not send yourself?" Shining asked. "This sounds like a threat you and Luna are perfectly equipped to deal with."
"Discord can track Tirek down to an exact location, whereas Luna or I would be fishing without an anchor," Celestia explained with reluctance. "And the longer it takes to track Tirek, the stronger he becomes."
Luna nodded. "Indeed, with each passing second, Tirek grows stronger still. It may not be long before he becomes powerful enough to drain pegasi of their weather controlling magic, or earth ponies of their magic that connects them to the soil and enables them to grow crops."
"So, what should we do in the meantime?" Shining Armor asked Celestia and Luna.
"For now, we will all go about our business as usual," Celestia explained, a smile forming on her face. "Hopefully, by the end of this week, everything will be back to normal, and Tirek will be back in Tartarus, this time in maximum security," Looking at Shining Armor she asked him. "Is there something wrong, Prince Shining? You seem troubled."
"I have not had time to examine your dreams lately, but from what I have sensed you are not at ease," Luna added, and cautioned. "Whatever might be eating at you, I would suggest you not keep it to yourself. When I tried to do the same with my guilt over Nightmare Moon, it took the form of a creature called the Tantibus. And through my negligence, I almost allowed it to become powerful enough to invade other dreams and escape into the real world. Had my sister not intervened, I fear that might have happened."
"Please, Shining, you must tell my aunts," Cadence encouraged. "This isn't going to go away if you keep it to yourself."
Shining hesitated for a moment in consideration, but then he reluctantly sighed and confessed. "Well, Princess Celestia, it's just that.... You raise the sun, Princess Luna raises the moon, and Princess Cadence is in charge of love, which finds a place in all but the blackest of hearts. Meanwhile, it seems like all I do is just stand around, smiling and waving. Is this really my destiny as Equestria's first alicorn prince? I don't mean to sound ungrateful, but I want to have a bigger role, I want to feel like I truly belong among the ranks of nobility, that I am worthy of my title. If I have to wait, how long must that be so? Please, tell me."
Celestia just replied in a warm yet serious tone. "I understand your concerns, Shining Armor. Your time will come soon, this I have forseen in my dreams. Though when, I cannot say with certainty. In the meantime, I suggest you return to Ponyville. Clearly, time away from your friends and sister has not done you well."
"But, what about Cadence, and Flash Sentry, and all the Crystal Ponies?" Shining asked Celestia.
"We've managed without you before, and we can do so again," Cadence encouraged. "You've more than earned some time off, Shining. You're as much of a hard worker as your sister was in her student days. I'm sure your friends will be glad to see you again, and I don't forsee any crisis' in the Crystalm Empire that I can't manage on my own."
Shining sighed, both Celestia and Cadence made fine points. And he was fairly certain Luna would tell him to go back to Ponyville as well. In any case, it was no use trying to argue with his wife AND the pony that was almost like a second mother to him. "Very well, I suppose some time off in Ponyville couldn't hurt," He agreed. "But, if any of you need for anything, you know how to reach me." And with that, he departed.