Luna slouched toward her sister's room, sans regalia and still wearing her fluffy moon slippers. After the third day in a row of bad sleep, she had given up any pretense of caring what the castle staff thought of her appearance. After she had dealt with whatever problem had cropped up now, she resolved to declare tomorrow a national holiday just so that she could get some sleep. There were deep bags underneath her eyes, her mane was limp, and her wings drooped. Worst of all, she'd been informed that it was an Emergency—one which warranted the capital E—so there had been no time for coffee.
Once she had learned the details of the supposed emergency, her mood had soured immediately, and her frantic gallop had dropped to a surly trot. The poor member of the Royal Guard that had alerted her didn't seem to understand why she had slowed after learning more about what was going on. He was, in fact, still hurrying ahead and looking back at her, unwilling to rush one of his rulers, though he clearly wished to.
It wasn't his fault. Given what Luna knew of modern Equestria, he could hardly be expected to know that when she got like this, Tia hated to be interrupted. The first time Luna had tried to interfere in what her sister termed a "personal duel", it had taken three weeks for the fur on her rump to grow back. To say nothing of what she had accidentally seen in her sister's tent later that night. She shuddered. The modern "sock on the doorknob" was a much more elegant solution.
Tia was a big girl. She could handle herself for a few extra minutes. Still, Luna had better check on her, just in case—the changeling queen was probably no pushover.
Luna was also sort of hoping that she could show up after the fact—she was reluctant to get involved in her sister and her soul mate hashing out several centuries of baggage. The fact that her sister's soul mate was a bizarre, alien, shapeshifting, love-sucking monstrosity certainly didn't help.
She sighed as she approached the door to her sister's chambers. The other guard posted at the door saluted, his expression a mixture of relief and terror. The guard that had been leading her resumed his post at the other side of the door, and was visibly fidgeting in his attempts to not prance nervously. "Thank goodness you're here, your majesty," said the first guard. "I assume you've been apprised of the situation?"
"Indeed. Rest assured, there is no need to fear. My sister is resilient—if she commanded you to remain uninvolved, I am certain that she judged herself more than a match for her foe."
Luna nodded at the two guards and without a further word, entered her sister's chambers.
She closed the door behind her, and surveyed the room.
Well.
There was no sign of her sister, and the room looked like been intimate with a tornado. It could have been worse, she supposed. There could have been holes in the—
Wait, no. It had been hidden by the remains of the drinks cabinet, but there was something embedded in the wall next to the kitchenette. Luna trotted closer to get a better look. It was some sort of black oblong, so deeply embedded that it was nearly flush with the wall. Luna worked her magic around it and gave it a single sharp tug, wrenching it free with a small shower of stony fragments.
Though squashed and cracked almost beyond recognition, Luna knew what it was immediately. Celestia's favorite—and heaviest—teapot. A solid cast-iron exterior, with a ceramic-lined interior, it had enough heft that most ponies struggled to lift it.
If Celestia had been willing to use it as a projectile, or unable to prevent it from being used as one, this was more serious than Luna had thought.
Ignoring the rest of the shattered bookcases, ashy remnants of the coffee table, and the vaguely changeling-shaped impression in the wall she had missed earlier, she trotted to the bedchamber door and slipped inside.
And stopped.
The first thing she noticed was that Celestia was asleep in the bed. Definitely asleep, and not unconscious, as indicated by the bone-rattling snoring. The second thing, which had stopped her in her tracks, was the changeling queen standing next to the bed, close enough that her chest was touching the covers.
At Luna's entry, Chrysalis' head whipped toward her, and she bared her fangs. Luna stood motionless, face impassive. Then, with glacial slowness, she lifted a single eyebrow.
After several seconds of silence, Chrysalis broke first. "What?!" she hissed.
"While I am glad my sister took my advice to heart," she said slowly, "I did not expect her to move quite so quickly."
Chrysalis frowned in confusion. "What do y—" Her face reddened and she choked as she grasped Luna's implication. "That is not what happened here!"
She made as if to step toward Luna, but was brought up short when one foreleg refused to move. Luna cocked her head and looked closer. Then, puffed up her cheeks in a mighty attempt to hold back a snicker. Celestia's forelegs were dangling off the bed, and wrapped around one of Chrysalis' legs. As Luna watched, Celestia's grip tightened, and she muttered something sleepily, then nuzzled Chrysalis' chest.
Chrysalis froze, and her blush intensified. She shot Luna a murderous look. "Not a word."
Luna was nearly shaking with the effort of restraining her laughter. "I believe it is traditional," she managed, "to allow soul mates their privacy to get to know one another. I see," she nodded at the destruction of the room behind her, "that you've already begun. I shan't intrude any further. I shall inform the guards that you are not to be disturbed. Good night!"
Luna gave Chrysalis a brisk nod, and left the room without a further word. Chrysalis ground her teeth together as she heard Luna finally give up the battle against her laughter in the other room. Then, she waited until she heard the outer door open and close. Then, she waited a little more. Then, she glanced around to make absolutely sure there was no one watching.
Finally, she leaned in close to Celestia, briefly nuzzled her cheek, then jerked away. She tried to ignore the way Celestia's happy smile sent a little spark of satisfaction deep into her core.
She was just in it for the love energy. That was all.
Really.