The sun was beginning to set, early in the day as it was wont to up in the far north. Everypony save Twilight, who was still out at the library, was gathered in the drawing room, huddled around the fireplace. Nyx was sprawled out on the floor, reading her way through her favorite book of pony tales. Spike was snoozing in a beanbag chair, toes practically in the coals of the fire. Peewee was sitting IN the fire, perched on the top log, cheeping happily. Shining and Cadence were sitting in a pair of comfy overstuffed chairs nearby, sorting through an enormous stack of letters and scrolls the butler had brought in on a silver tray, sorted into two piles.

Cadence mumbled idly over one roughly hoofwritten letter. "Oh how nice," she smiled.

"What is it?" Nyx asked.

"A letter from a schoolfilly," Cadence said. "Your uncle Shining and I get fan letters every now and then. This one is writing to me and says she thinks I am very pretty, and hopes I have 'a very nice time being Princess.' " Cadence and Shining both chuckled. Cadence pulled out a postcard and a quill. The quill danced across the card. " 'Dear Berry Bloom, thank you for your nice letter, it was very sweet of you. Love, Princess Cadence.' " She floated the card over and let it rest on Spike's belly. "Spike... outgoing mail!"

"What? Oh, gotcha." The sleepy eyed dragon spat a little green flame on the paper. It vanished in a puff of sparkly smoke. He went right back to drowsing.

"That should make her day," Cadence said with a smile.

"Do you answer them all?" Nyx asked.

"As many as we can," Cadence said. "When you're a ruler, it never hurts to do anything that helps raise goodwill." She magically flicked another envelope from the stack next to her. "Hmm. This one is from Auntie Celestia."

"Hmm, that's nice. Anything important?"

"No, just she and Aunt Luna sending their love, etcetera..." Cadence scanned down the letter. "Oh, and Auntie Celestia wants to know if you've been feeling well-- if you've had any unusual magic surges or little growth spurts, or if you've felt any itching down your back, that sort of thing." Cadence frowned. "That's rather oddly specific..."

"Can't say as I have," Shining said. "well, now that you mention it I do get little tingles or itches down my back now and then lately. I think my uniform jacket needs refitting." He scratched his back with a hoof absentmindedly.

"I get back itches when my wings aren't preened right," Nyx contributed, flexing one of her little wings by way of demonstration.

The three of them pondered this a moment, then shrugged. "Just another one of Auntie Celestia's odd little jokes," Cadence guessed.

Shining Armor picked up an envelope from his own stack-- and hastily stuck it down in the wastebasket on the other side of his chair, pulling a face. He wasn't quite fast enough though; Cadence spotted him out of the corner of her eye. "Shiney, what was that?"

Shining Armor flushed. "Just junk mail," he half-lied.

Cadence wasn't buying it. "Shiniiing...." she said in a warning tone. Sheepish and annoyed, Shining Armor levitated the unopened letter back out of the waste can with a moue of distaste. "Just another one of those letters," he said.

"Those letters?" Nyx repeated, peering at the envelope floating between them. Was that lipstick on the seal? "Omigosh, is somepony writing mushy letters to Uncle Shiney??"

"Wuh oh, trouble in paradise," Spike muttered. He made as if to get out of his beanbag. "I'm outta here--"

"Oh stop it you two," Cadence scolded, amused. Shining Armor, for his part, sat there looking embarrassed and disgruntled. "Every now and them some schoolfilly--"

"Or dingy mare," Shining added in annoyance.

"It's a filly, Shining. Glitter and puffy gel pens. Anyway, there are a few fillies out there who get a crush on my handsome stallion--" she leaned across the end table to give Shining a kiss on the cheek "-- and they take to writing him 'mushy letters,' as you put it Nyx. Some all the way from Equestria." Her eyes twinkled. "You should see the fillies when we go out together on a parade or the like. It embarrasses him to no end."

Nyx giggled. "You mean, they're all--" she lay her fetlock across her brow-- " 'Ohhh, he's sooo handsome,' and blowing kisses and throwing kerchiefs and stuff?"  Nyx squealed with laughter at Cadence's nod. Shining just grumbled and slouched down in his chair.

Cadence gave him another kiss, this time on the ear. "You are just so adorable when you're flustered."

"I didn't see any of that when we went out the other day," Spike noted.

"I made a point of avoiding where they might congregate," Shining said dryly.

"So what do you do when they won't stop sending you love letters?" Nyx asked Shining, still giggling.

"I let her handle that," Shining said, waving his hoof at his wife.

Cadence opened the letter and scanned over it. "Yes, little hearts all over pink stationery," she said. She gave a sniff. "And, yes, possibly a half-gallon of perfume--"

"Make it stop," Shining moaned. Nyx and Spike laughed mercilessly.

Cadence pursed her lips. "Well, I don't want to be mean to the silly little thing, but really, I think this is her third letter and she really needs to stop..." she pulled an eight by ten glossy out of her little basket of letter-writing materials. "I think an autographed copy of our wedding picture should drop the hint, without embarrassing her too much in mixed company," she said. 'Thank you for your kind letter, Diamond Tiara, warmest wishes from Princess Cadence and Prince Shining Armor--"

"DIAMOND TIARA??" Spike and Nyx shrieked. Shining Armor and Cadence looked on in bewilderment as the two of them collapsed, shrieking with laughter. Spike rolled clear out of his beanbag chair, clutching his gut and howling; Nyx lay there face down on the rug, pounding the floor with a hoof and laughing till tears rolled down her cheeks.

It took several minutes for them to calm down-- and a couple minutes more for Nyx to wipe her face and get her hiccups under control-- and then they told the royal couple who Diamond Tiara was. "She's your classmate?" Shining Armor asked in disbelief. Nyx hiccuped again and nodded, unable to wipe the grin off her face.

"Wait'll Sweetiebelle and Scootaloo hear about this--!" she giggled.

Cadence got upset. "Nyx! Now you're not going to use this against her, I won't have it. I forbid you to tell her you know."

Nyx's face fell in dismay. "Awwww...! But Aunt Cadennnce...!"

"C'mon, Princess," Spike had to say. "This Diamond Tiara really is a little toad. Just a little teasing...?"

"No." Cadence frowned. "Now promise me you two aren't going to breathe a word about this," she said. "Not to her, not to your friends, not to anypony."

The two youngsters slouched, but they went through the motions. "I promise not to tell anypony. Cross my heart and hope to fly, stick a cupcake in my eye," they droned. At Cadence and Shining's stare, Spike said "Pinkie Promise. You remember Pinkie Pie, right? From the wedding?"

"Nobody breaks a Pinkie Promise," Nyx said with almost frightening seriousness.

"Ah, yes. So I've heard," Cadence said. Applejack had told her the story of the time Pinkie Pie had thought she'd broken a Pinkie Promise. Eek. At least she knew Nyx and Spike were serious.

"Do you ever get letters like that from colts?" Nyx asked Cadence. Ah the artlessness of youth.

Cadence smiled. "No, not really. Colts don't tend to do that sort of thing... write 'mushy letters' or the like. A colt is more likely to give you flowers, or chocolates, or maybe buy a HoofMark card..." she chucked. "They're adorable in person. They get all flustered and tanglehoofed and tongue tied when they see you..."

"Is that how you know a colt likes you?" Nyx asked, her inquisitive little mind filing the information away for future use.

Cadence didn't miss that little uptick in curiosity. She smiled enigmatically. "It's one of the ways you can tell," she said. She leaned over and gave Shining another nuzzle behind the ear. "Isn't that right dear?"

"Oh for--!" Shining suddenly shouted, startling her.  "Wait, what? No, not you--" he grumped and held out another lipstick-sealed envelope. "It's another one."

Cadence's magic aura plucked the envelope from his hoof. Cadence 'hmmed.' "Another one from Ponyville," she said.

Spike and Nyx shot one another a look filled with disbelieving glee. It couldn't be--

"From Miss Silver Spoon--" Cadence continued.

It was this scene that Twilight walked in on;  Cadence and Shining Armor sorting mail, Spike and Nyx rolling back and forth on the floor in hysterics. "Well, at least you all seem to be having a good time," she said warily. "What on earth is so funny?"

Nyx and Spike sat up, looked at her, looked at each other, and exploded into smothered giggles. "Can't say," Nyx said in obvious dismay.

"Pinkie Promise," Spike added between chortles.

Twilight started to say something, hesitated, started to say something again-- then shook her head, giving it up for a bad job. "I'll probably find out later," she sighed. "Spike, Nyx, would you go on to our suite? There are some things I have to talk about with your Aunt and Uncle."

At this Nyx started up the age-old whine. "Awww, but it's only six thirty!"

Twilight's response was firm. "And I'm not saying you have to go to bed, I just need you to give Aunt Cadence, Uncle Shining and me some privacy for a while. You can stay up and read or play a board game or whatever you like, but I need you out from underhoof for now. Go on..." She gave the reluctant filly a nudge and got her on her feet. Nyx grumbled but she obeyed. "You too Spike."

"Gimme a sec, just gotta get Peewee de-sootified, here," Spike said. He reached into the fireplace and plucked the phoenix chick out of the coals and gave him a cursory dustoff. Peewee cheeped and ruffled his feathers, scattering soot around him. Satisfied, Spike set the chick on his shoulder and trotted off after Nyx.

The adults waited until they heard a door close. Then Cadence and Shining Armor turned to Twilight. "Okay, so what's up, Twiley?" Shining Armor asked, cocking an eyebrow.

"Cadence, Shining," Twilight said, pulling a transcribed copy of Level Head's journal out of her saddlebag, "I've learned some things about your kingdom's past, and Equestria's, that may change the whole world..."

Twilight spent the next hour relating the true Hearthwarming story to her brother and sister-in-law. There were copious notes and charts and maps; she had spent several hours after her discovery of the journal scratching together what correlated information she could from the scrambled shelves of the great library. It was all true; there were just too many historical and archaeological anomalies that suddenly had an explanation; too many odd puzzle pieces that suddenly fit.

When she was done with her presentation, Shining Armor and Cadence sat back, stunned. "This is, this is incredible," Cadence said. "Why haven't we heard any of this? Why wasn't I told?"

"Who would have told you?" Twilight asked suspiciously. Darn it, if Celestia was playing cryptic again...

"Twiley, Cadence is the heir apparent of the Crystal Empire," Shining Armor said. "She's related to Princess Celestia on her mother's side. But her father's side comes from a line of unicorns that... well, that we think is descended from the former rulers of the Empire before King Sombra usurped the throne."

"Family records were a little hard to come by after the Empire disappeared," Cadence said wryly. "We just know my great-great-great-however many greats grandfather and grandmother fled the Empire before it fell.

"I was raised on stories of the lost Empire. While Celestia and Luna kept it quiet, I was basically told from the very beginning about the lost Empire, that I was the heir to the throne." She looked back at her flank and smiled. "That's how I ended up with my cutie mark... the crest of the royal family of the Crystal Empire."

Her smile faded; she got to her feet and began to pace. "But in all this time I never heard anything about the origins of my kingdom. About the Crystal Heart, about the exodus, about any of it. Why would they not tell me all of this? And why didn't I learn about it here?"

"They may not have known the story," Twilight said. "Even before King Sombra, there was a concerted effort by the nobility to... suppress anything that might be embarrassing to the royal family or unicorns in general. Which at the time were one and the same thing. The reason the legend persists is because it was passed down as folklore, from parent to foal, in secret. There are at least five major oral versions of the, I suppose you'd call it the Crystal Hearthwarming-- The differences are fairly minor, but they are there.

"As to the library, I found out they've been doing things the way they did during King Sombra's reign: Hiding any books from you that they thought might get somepony executed."

"Executed?" Cadence gasped.

Twilight Sparkle nodded. "Simply being in possession of the wrong book during his reign got ponies beheaded." Cadence looked sick. "And he wasn't the first, either. Most of the unicorn rulers limited themselves to ruinous fines or even imprisonment. All the same..."

Twilight paused. "I don't think knowing that you are the rightful heir to the throne would be much of a comfort to the ponies here," she said.

Cadence turned and buried her head in Shining Armor's shoulder. "How in the Maker's Name am I supposed to fix that?" she lamented. Shining nuzzled her consolingly.

Twilight pressed on. "There might actually be an answer to that in the story," she said. "Remember what I said? The Crystal Heart was crafted by earth ponies. Not by unicorns. Chancellor Pudd-- Chancellor Level Head, Smart Cookie, Clover the Clever, Private Pansy... they were all engaged in research into earth pony magic. They were successful enough over the years that they were able to craft defenses for the Crystal Empire, and even to make the Crystal Heart."

"I don't see where you're going with this, Twiley," Cadence said.

Shining Armor straightened. "I think I do, sweetheart," he said. "Half the reason that the ponies here are so resentful and angry about the past is because they feel helpless. For all that earth pony magic can do, it's-- it's still just a plowshare to the pegasi's sword and the unicorn's shield. But if we could give them back their heritage, magic that the Founders knew... real, potent earth pony magic...."

"Level Head's lost tomb," Twilight continued. "It says he and his grandson Smart Cookie were buried 'with their greatest treasures--' "

"Which could only include their books and research," Shining armor said.

"Which would revolutionize magical studies in ways we couldn't imagine!" Twilight finished, practically bouncing on her hooves in glee.

Cadence's eyes went wide.  "To say nothing of what it would mean to find the long lost tomb itself...recovering such a national treasure..." She looked at Twilight. "Twilight Sparkle, I hope you have an extended vacation planned, because as Princess I am commissioning you to find the lost tomb of the Founders!"

"Yes! Oh wait, we need to inform Celestia and Luna about all this," Twilight said. Muttering to herself, she got out scrolls and ink. "Spike! I need you to-- oh right, sent him to our room..."

"Why'd you send him and Nyx out of the room anyway?" Shining Armor chuckled.

"Because little pitchers have big ears," Twilight said with a wry twist to her voice. "And bigger mouths. This is sensitive stuff, and I'd rather not have either of them blurting it out by accident-- Pinkie Promise or no Pinkie Promise. It's better that they know as little as possible till we have the whole story in one piece and ready to be heard."

"So what are they saying now?" Nyx asked. She was lying on the four-poster bed in the middle of the room, half-reading her book of pony tales and half watching her foster brother.

Spike looked over at her. He was leaning against the wall, ear pressed to a drinking glass. "Wow," he said. "Looks like we're all gonna be staying here a lot longer. Twilight's found out about some super secret long lost treasure tomb here, and Princess Cadence wants her to go and find it."

"Like in Daring Do? Cool," Nyx said.

Unknown to most, the Crystal Palace was riddled with what some would call 'secret passages...' in actuality servant passageways, made so that the staff could come and go through the palace unobtrusively and without tripping over the residents or guests. They were accessible through unobtrusive or even outright hidden doors, which were almost impossible to find unless you were deliberately shown or were cunning enough to know what to look for.

Naturally Nyx and Spike had found them all within a few hours of arriving.

There was one separating the drawing room and the guest suite bedroom. The instant they had gotten to the guest suite, Spike had beelined for the hidden door, glass in hand, and had positioned himself out in the servant's passageway with his ear (and glass) pressed to the wall. Nyx had fretted a bit, but had eventually decided that since Spike was in the hidden hallway for their room he was technically still inside the suite, so she let him eavesdrop without tattling on him. Besides, as Spike had argued, he was Twilight's number one assistant, and he had to do this sort of thing just to stay one jump ahead of her.

He was also being nice enough to keep her updated on what was going down. That was a big plus. Ever since her time as Nightmare Moon, she hated being kept out of the loop. Spell Nexus and his flunkies had done it to her, and it had caused no end of trouble for her. "Huh," Spike said. "I can't believe it. The whole Hearthwarming Day story--- turns out it was all wrong!"

"Really?" Nyx said, a little worry creeping into her voice. She'd gotten wind of this Hearthwarming Day thing from her friends, and like any foal the idea of a holiday with games, stories, candy and presents had appealed immediately. "You don't think they'll cancel it, will they?"

"What, Hearthwarming Day? Nah," Spike said. He reflected for a moment and his brows flattened. "But man are some folks gonna make a rumpus about it when they find out, oy. " He adopted a fake, nasally voice. "But it's traditioooonnn,' 'But it's inaccurraaaaaate,' blah blah blah blah blaahhh... It's enough to put you off your eggnog." He grumbled. "And then there are the ones who complaint about Santa.'But Santa isn't REAL.' How hard do you have to work at it to be offended by a fat guy who gives away free stuff?"

"Santa isn't real?" Nyx asked.

Whups. "Umm... not exactly." Nyx gave him a look. "Actually... no."

To Spike's surprise she took the news well. "I kind of figured," she said, only a little disappointed. "I measured our chimney. No way in heck." She rolled over on her back and looked at Spike. "So why does everypony keep talking about him?"

"I dunno," Spike shrugged. "Just a nice story somepony made up."

Nyx thought about it a bit. "I guess it's like when ponies say 'a little birdie told me,' " she theorized. "When they're giving away presents and don't want to tell who got it, they say 'Santa got this for you.' "

Spike shrugged. "I'll go with that."

Nyx rolled back over on her stomach. "Spike?" she asked.

Spike was distracted, trying to hear what Twilight, Cadence and Shining Armor were saying. "Yeah, what?"

"Are you still... angry at me?"

That got Spike's full attention. "About what?" he said.

Nyx looked at him. "After I, after I came back," she said. "You were afraid of me. And you hated me, I could tell."

"No, I--"

"Did so," Nyx said with finality. "You hated me, and you were scared of me too. I could tell. I'm not stupid."

The words stung. Spike came back into the room, closing the hidden door behind him. "I... I was angry at you," he admitted. "And scared of you, yeah." He stood there at the foot of the bed, twiddling his thumbs awkwardly. "You turned into Nightmare Moon. You banished Celestia to the sun and Luna to the moon! You locked the cutie mark crusaders up, and threw Twilight in a dungeon. You hurt a lot of folks, Nyx." Nyx bit her lip but said nothing.

The words burst out of him. "You nearly hanged Twilight, Nyx! Of all the things you did, that was the worst! If she'd died, I--"

"I didn't!" Nyx protested out in horror. "That was Spell Nexus! I saved her!"

Spike swallowed. "I know that now, Nyx. But back then I didn't. Nopony would tell me exactly what happened. Not for ages. They thought I couldn't handle it." He scowled. "Yeah, and me not knowing what happened was so much better." His face softened. "I-- when I thought you'd done that, I-- I did hate you." There, he'd said it. It hurt, but he said it. "I'm sorry I let myself feel that way."

To his surprise, Nyx leaned forward off the end of the bed and nuzzled him. "It's okay," she said. "I... kind of hated myself after all that, too."

Spike was taken aback. "Why do you forgive me?" he asked.

"Why did you forgive me?" Nyx said back.

Spike shuffled his feet. "Because... because you said you were sorry,and you meant it," he said. "Because you changed your mind and said you were wrong."

"And so did you," Nyx said. She broke the somber moment by 'boop'ing him on the nose with her hoof. Spike grinned. "But why did you change your mind?" Nyx asked. "I know you were angry at me, and scared of me. Why not anymore?"

Spike's smile turned droll. "Well first off it's kind of hard to be scared of Nightmare Moon when she's scared of Fluttershy's chickens," he said.

"Heyyyy," Nyx complained. "Those chickens have sharp beaks!"

"So? They peck me all the time, I'm not scared of them."

"Yeah, well I'm not covered in thick tough scales," Nyx said. "I'm softer and smooshier than you." She used her hooves to smush her cheeks in for illustration.

"Okay okay," Spike chuckled. He suddenly looked abashed. "But, the real reason I stopped being angry at you is Twilight talked to me and reminded me of some things I did..."

"But I don't trust her!" the little dragon finally blurted out. "I can't! I just can't forgive and forget, Twilight. Not after all she did!" He sat down on the floor, arms crossed, his face a mixture of defiance and unhappiness.

Twilight didn't get angry or shout. She just lay down on the floor next to him. "I know, Spike," she said. "I know it's hard to forget what she did. But she's our little Nyx again. Maybe a little worse for the wear, but it is her." She nuzzled the dragonling; he pretended to ignore her. "Please try to remember you love her. She could use somepony-- or somedragon-- like you right now."

"Why?" Spike demanded to know.

"Think about it, Spike. Think about what she's been through. She lost control... turned into a monster... did terrible things... hurt and frightened her friends... nearly destroyed the town... "

She rested her chin on the top of his head. "Hmm. Or is that somepony else I'm thinking of?"

"Hey, you promised never to bring that up again--" Spike huffed. His bout of 'greed-growth' was still a sore point with him.

Twilight chuckled. "Well I had to this time," she said. "Spike, you're probably the only one in Equestria other than Princess Luna herself that gets what Nyx is going through right now. And I'll bet she could really use a big brother who understands her like that. We all forgave you for what happened; please try and forgive Nyx in the same way."

She stood up to go back into the library, and looked back. "You know, there's one other thing that you and she have in common," she said.

"Oh really? What's that?" Spike asked, curious.

"You were brought back by somepony you loved."

"...Wow. You really turned into a giant dragon and... oh, that's why you didn't want to see that monster movie," Nyx said.

Spike nodded. "Yeah. They think it happened so fast because my egg was hatched with unicorn magic."

"So being greedy can make you grow into a giant?" Nyx frowned. "But I've seen you be greedy all the time!"

"Like when?" Spike said belligerently, hands on hips.

"Like any time you get near a tray of Pinkie Pie's cupcakes," Nyx teased. "You snarf 'em down like you eat out of a trough." She pulled her nose up with her hoof and made piggy noises at him.

"Heyyy..."

From elsewhere in the royal quarters came the call: "Spike!"

"Whups, that's my cue. She probably wants to write the Princesses, call it a hunch..." Spike grabbed a quill and ink and an armload of scrolls and hustled for the door. He stopped briefly. "Nyx? I never said it before but-- I'm glad you're back."

Nyx smiled. "Me too."

Spike waddled out the door.