"There's one thing I don't get."
Gallus rolled his eyes at Ocellus. "You must really be an egghead then, 'cause there's a ton of stuff I don't get." He ducked a moment later to evade the crumpled-up paper ball that Smoulder threw at him from across the library table.
"Really though!" The changeling's elytra buzzed. "Ever since the, um, big confrontation? I've been curious and studying about the Elements, and I think I discovered something." Ocellus turned the book she was reading towards the others. "Aside from Princesses Celestia and Luna, every group that has controlled the Elements is made up of six members. The Pillars, the Bearers, the ones from the mirror world that Princess Twilight talked about... and us."
Smoulder leaned back in her chair, arms behind her head. "Yeah. We're awesome."
Ocellus shook her head. "But the books are wrong! There aren't six, there's always seven. The Pillars have Stygian, the Bearers have Spike, and the mirror world has Sunset Shimmer." She paused, looking around at the others to see if any of them would get it.
With a snap of her claws, Silverstream did. "But there's only six of us!" Sort of.
It was Gallus who finally got it. "So who's our seventh?" He looked back and forth between the rest. "I mean that's what you're getting at, right? That since there's always seven, we must have a seventh too."
Ocellus nodded. "Exactly. I'm trying to figure out who it would be."
"Well, I bet it's the Cutie Mark Crusaders," Sandbar volunteered. "They're tutors here at the School, they're a big help when we need them and they're the ones that delayed Cozy Glow so we could get to the artifacts! Plus they're totally great at friendship and their sisters are all Bearers so they're a perfect fit!"
Smoulder blew a puff of smoke in Sandbar's face, sending him coughing. "Perfect except for how they're not."
Defensively, Sandbar jabbed his chin at the dragon. "What's wrong with the Cutie Mark Crusaders?"
"Well for starters there's three of them," Smoulder pointed out. "I know they act together like one pony a lot but there's really three of them. Trust me. I counted." Her burning sarcasm was met by Sandbar rolling his eyes. "And besides! They've got their own adventures without us, and we've got plenty of ours without them. No way they're our Spike."
They were good points, which did nothing for Sandbar's mood. "Well who do you think it is then, Smoulder?"
Lounging in her chair, the dragoness didn't hesitate. "It's obviously Cozy Glow."
"Cozy Glow?!"
"Cozy Glow," Smoulder repeated. "She showed up around here the same time we met each other, she went on a couple of adventures with us and she assisted us without being part of the group."
Gallus tossed the paper ball back at Smoulder - it bounced off her snout, making her wobble and flail in her canted chair. "Yeah, terrible assistance that caused more trouble than it solved. Plus, you know. She was evil."
Smoulder crossed her arms over her chest. "So what? Stygian was evil too. And so was Sunset Shimmer."
"And they both turned out good after being rainbow lasered," Gallus dryly sneered. "Cozy just got angrier."
"Oh! Oh!" Silverstream popped up from behind Gallus' chair, sending him sprawling with a yelp. "What about my brother Terramar? He's really cool and smart and I'd really love to have him around because I love you guys but it's not exactly the same without anygriff being here and he's family too!" She leaned closer to Sandbar and winked. "Plus I think he really likes Scootaloo." Silverstream nudged Sandbar with her elbow meaningfully.
Sandbar's expression lacked absolutely any amusement at the hippogriff's antics.
Fortunately, Ocellus provided a distraction. "A--Actually, Silverstream, I think you're getting it wrong. We're trying to figure out which creature already is our seventh, not holding try-outs for the position."
"Oh." Silverstream deflated with a frown of deep thought. "I guess that makes more sense. But if it is Cozy Glow we really should get a replacement."
Sandbar rolled his eyes - only to be elbowed by Gallus. "Hey, she's right," noted the griffon.
Grudging grumbles around the table conceded that point.
"But wrong about the rest," Gallus amended rather late. Everycreature else looked at him questioningly. "I mean, come on. Look at it - someone that's helped us through things? Who watches out for us, backs us up and is there for our adventures?" The griffon looked around expectantly at the others, unsure how they weren't immediately grasping his point. "It's obviously Guidance Councilor Starlight."
The others looked back and forth between themselves, considering the option. It was finally Silverstream who voiced her thoughts. "Mmmm, I dunno. I mean, she does help us a lot but usually not when there's an adventure? She mostly just helps us do homework and study."
"Yeah," Sandbar added, "Plus she's, like, Headmare now. How can she be our assistant when she's in charge?"
Grumbling, Gallus couldn't find a reason to object.
Ocellus frowned in thought. "Yona? Who do you think it is? You haven't said anything yet at all."
"Which is unusual," Gallus added reflexively right before the Sandbar tossed a pencil at him.
With a sigh as weighty as herself, Yona finally joined in. "Yona not say anything because Yona think this stupid." When everyone else looked at her quizzically, she reluctantly elaborated. "Yaks not dumb, understand basic causality. Just because was seven does not mean will be seven. Past does not cause future. Besides! Pony Princesses use Elements before - do friends pretend there five other secret Princesses hiding then?"
The implication of secret Princesses made Sandbar shift uneasily. Ocellus was not so easily dissuaded. "I already said that was an exception. And it isn't really about causality, Yona. Numerology is a proven part of magical theory and in Headmare Twilight's class--"
"Numerology is dumb," Yona pronounced. "Numbers not absolute - Yaks have entirely different numbering system." She held up her cloven hooves and counted on them. "One, two, three, four, many." With the last number she simply spread her forelegs wide. "Yaks not even have word for six. Numbers not meaningful - is meaning we give numbers important."
All around, the six lapsed into quieter thought. It was obvious there was no simple answer and that they weren't going to agree. But there had to be an answer, even if it was that Yona was right and there wasn't one.
Finally, it was Silverstream who broke the silence. "Why don't we just ask Headmare Twilight? I'm preeeetty sure she's still here packing up her office."
Sandbar popped up to his hooves. "That's a great idea! After all, nopony's done more research into the Elements of Harmony than she has. I bet she's already got this figured out."
A smoke-filled snort came from Smoulder. "If she already knows the answer, I bet she won't tell us. It's probably another test she wants us to figure out."
As they all got out of their seats, Gallus took a moment to languidly stretch. "Yeah, well, we better hurry either way. Once she's done packing I doubt we're gonna see her again until after the coronation. So c'mon already - I don't wanna have to listen to everycreature debate this any more than I have to."
The Office of the Headmare was painfully empty. While not a place the students wanted to end up, the office had always been warm, inviting, and slightly reminiscent of a library. Now the walls were bare, the shelves empty and the desk clean. The full contents of the room sat in a shockingly small number of boxes, beside which Twilight Sparkle and Spike were taking final inventory.
The Headmare - the Princess - turned as her students came in. "This is a surprise! I didn't expect anycreature to see me off until the train station." Without even waiting for a response, Twilight wrapped her hooves around the nearest - Silverstream - and hugged her.
Ocellus stepped around the hugging pair. "Um, actually? Headmare-- Princess Twilight? We are going to be there to say goodbye but we had a question first."
"Oh!" Twilight laughed and sat down on top of one of the packed boxes. "I suppose that while I'm no longer Headmare, I can spare a few minutes to teach one last lesson to my favorite students."
The six arranged themselves in a loose semi-circle around the Princess as Ocellus outlined the issue. "Well, after learning more about the Elements of Harmony, we found that there's usually a seventh member instead of just the six that are always mentioned. And we were trying to figure out who our seventh member was."
"And by trying to figure out, she means arguing," Gallus added.
Twilight pursed her lips tightly, suppressing a laugh.
Silverstream lept into the conversation. "So Sandbar said it was the Cutie Mark Crusaders and Smoulder thinks it's Cozy Glow and--"
A purple hoof raised, silencing the recap. Twilight sat regally on her crate of books, holding court over the otherwise empty office. "First I must say that I'm proud of what you've found and that you're still trying to learn. I know there's the temptation to be comfortable with what you do know instead of striving for what you can know, and it warms my heart that the six of you are still trying. And Ocellus, you are correct. That there are seven rather than six is missed far too often by historians and writers. Dismissing the contributions of Stygian are what drove him to become the Pony of Shadows in the first place. And I know that the lives of me and my friends would be far different if we hadn't had Spike there to aid us."
Twilight turned and smiled at her assistant-slash-younger brother. Spike, in turn, smiled back.
"That's why, since I'm leaving for Canterlot, I had always intended to leave Spike behind to serve as the seventh for your group as well."
Spike's jaw dropped. The six students gawked in turn at Twilight's unexpected betrayal.
"He will serve you well," the Princess pronounced. "He's noble, brave, well-organized and--" And Twilight descended into wild giggling. "I'm sorry, I'm sorry! The look on your faces!"
Sourly, Spike crossed his arms. "That wasn't very funny, Twilight."
She reached out a hoof and stroked the small dragon's head. "I would never leave you like that, Spike. Ever. Even if I somehow went completely Twilinanas and actually did that, how would I ever get anything done without you?"
Spike managed to keep looking grouchy for about seven seconds before leaning in to hug Twilight. "I know you wouldn't. Not really. I just--"
Much more loudly than was strictly necessary, Smoulder cleared her throat. "Before this gets too sappy, could we get on with it? I've got a bet you know but won't tell us."
Twilight and Spike separated, each with a mild blush of embarrassment. "Er, yes. Of course!" The Princess straightened back up. "All joking aside, I'm afraid you're going to lose that bet Smoulder. Which is good because even if I'm not Headmare anymore I can't approve of gambling on school grounds." A budding lecture came to a screeching halt as she noticed Gallus getting ready to demand an answer again. "I do know the answer and I am going to tell you."
"It's someone that you didn't meet immediately after arriving here at the School," Twilight outlined, "But when you did meet them, it was very memorable. And while they haven't been on every adventure with you, they've always been helpful in their own way. In fact, without them I don't think you six would be anywhere close to who you are today."
There was silence for a long moment before Smoulder smugly looked to the others. "Told you she was gonna make it another test."
Twilight facehooved. "It isn't a test. It's the Tree."
Silence hung for a moment. "But Sombra destroyed the Tree," Sandbar eventually noted.
"True," was Twilight's counter, "The Elements themselves and the Tree of Harmony were destroyed. But the spirit of the Tree still spoke to you all in your dreams after that happened." She smiled broadly at a memory. "When my friends and I confronted Nightmare Moon, she destroyed the Elements as well. And then they reformed under the light of our friendship. And under yours, the Tree was also reborn. It regrew and reblossomed from your memorial. I have a feeling that soon enough, it will be able to manifest to you again."
The six students looked between themselves, considering the Princess' words.
Ocellus ventured her opinion out. "I'm not sure if we all agree that you're right, Princess Twilight. But I think that our friend coming back again is something that makes all of us happy - no matter of it is our seventh or not."
"It not matter who seventh is," Yona added firmly. "This argument show we have many friends who help! Who cares who seventh or eighth or many? It not matter."
Smoulder voiced the thoughts for them all. "Yona's right. It doesn't really matter, does it?" The others nodded solemnly in agreement.
Until Sandbar stopped cold. "Wait. If it doesn't matter, doesn't that mean what Yona said before about causality and numbers not mattering was right?"
Yona tried not to smile too widely. "Yes, because yak way is correct way and Yona is right. Friends just need learn to trust yak wisdom."
Loudly, Gallus groaned. "And here we go again...."
Twilight just laughed.