What seemed like hours had passed.
Mostly because it had, in fact, been hours.
The special-ordered ice sculpture was little more than a puddle. Matilda had come to take Cranky home. Derpy had curled up in a corner of the banquet hall and was mewling softly in her sleep. DJ PON-3 was idly drumming with the cutlery, her head still bobbing to her own beat.
Celestia was beyond annoyed, sitting on the red line between peeved and ticked off.
Eventually, Twilight Sparkle returned, two unicorns in tow. "We're baaaaack!" Twilight called cheerfully.
Celestia turned around and stared at her, eyes narrowed. "Twilight Sparkle," she said in a stern tone.
Twilight's ears wilted. "Uh-oh."
Celestia rose and trotted slowly, ominously toward her. "Explain," she commanded, "why you invited these guests and myself to a dinner party, disappeared without an explanation, and never bothered to see to the needs of your guests?"
"Umm..."
Starlight Glimmer stepped forward. "It's...it's my fault, Your Majesty," she said nervously.
Twilight sighed. "No, Starlight, it's—"
"No, let me finish," Starlight said. "Twilight gave me an assignment to make a new friend. I did." She gestured with a hoof at Trixie. "But my new friend had a prior commitment this evening. I—"
Trixie blinked. "You stood up Princess Celestia to help me with my magic act? Are you insane?!" She turned Starlight to face her. "If you'd told me you were expected by Princess Celestia, we could've waited to do the Moonshot Manticore Mouth Dive!"
Celestia's ears perked up. "Hoofdini's famous trick? You...you pulled it off?"
Trixie reared slightly. "Y-yes...with assistance from Starlight Glimmer."
"I, umm...teleported her out of the manticore's mouth into the box," Starlight said.
"Well, yes, that is how the trick works," Celestia said.
"It is?!" Trixie and Starlight exclaimed.
Twilight rolled her eyes. "How else were you supposed to pull it off?"
Trixie and Starlight stared at each other. Trixie groaned, facehoofing. "In hindsight...it is sort of obvious," she admitted.
Celestia raised an eyebrow. "Are you, by any chance, Trixie Lulamoon?"
"I am, yes," Trixie said. "You...you've heard of me?"
"You have...a bit of a reputation."
Trixie cringed.
"She's trying to make amends for that reputation," Twilight said hurriedly. "And...and I wasn't making it easy for her. I left because I thought..." She sighed. "I thought Starlight making friends with Trixie probably wasn't a good idea. Because I still didn't really trust Trixie."
Celestia gave Twilight a measuring stare. "Yes, let us talk about the ponies you choose to trust," she said. "You chose to forgive a unicorn who stole the Cutie Marks of an entire village of ponies, brainwashed them to be her obedient slaves, then misused powerful time travel magic to exact her revenge against you and your friends."
Starlight cringed. Trixie stared at her.
"And yet, you actively attempted to sabotage—if I'm understanding what happened tonight—Starlight Glimmer's attempts to befriend a showmare who once fell victim to a cursed magic amulet, and before that, was—at worst—a minor annoyance?"
"Trixie was not an annoyance of any kind!" Trixie protested. "Twilight Sparkle's friends heckled Trixie's performance, then two idiot colts from Ponyville decided to bring an Ursa Minor into town and Twilight Sparkle upstaged Trixie in vanquishing it!" Trixie waved a hoof. "Trixie is a blameless victim of circumstance!" Then, remembering who she was addressing, she ducked her head and offered a sheepish smile. "Ahem, Your Majesty."
Celestia turned her gaze back to Twilight, once again raising an eyebrow. Starlight Glimmer matched her expression almost perfectly. Twilight retreated two steps, hanging her head. "In my defense, Trixie didn't bother to stick around to explain her side of things. She just...left. If...if she'd told us any of this, maybe..."
Celestia sighed and shook her head. "And on top of everything else, you made no attempt to explain the situation to me before you simply left a room full of guests in the lurch."
Twilight's ears flattened against her head. "I...I'm sorry," she said, scuffing the floor with a hoof. "I'll...I'll apologize to everypony for—"
Celestia raised a hoof. "Before that, I want to see if you understand what you did wrong tonight."
"Pretty much everything," Twilight said immediately, grimacing. "I left you, Cranky, Derpy, and DJ PON-3 hanging. I tried to interfere in Starlight's attempt to make a friend on her own, which was the assignment I gave her in the first place. I chose not to trust Trixie simply because I was prejudiced against her. I nearly wrecked a friendship before it truly had a chance to begin." She sighed. "Some Princess of Friendship I turned out to be."
For the first time that evening, Celestia smiled her gentle, reassuring smile. "Twilight. Being the Princess of something doesn't mean you're the master of it. Friendship isn't something anypony can ever truly master. It's something you have to work at constantly. You may live to be as old as I am and never learn everything there is to learn about friendship. In the past year and a half, you have, I believe, seen how much you still have to learn."
"I guess I have," Twilight said.
"You may find that your student has as much to teach you as you have to teach her," Celestia continued. "Just as I learned much when you were my personal student. Including how not to repeat the same mistakes I made with Sunset Shimmer."
"I think I've already learned something from her," Twilight said. "And from Trixie."
"Good," Celestia said. "Then you can consider that lesson in the coming weeks, because the three of you are not to leave this castle again until Trixie learns to safely teleport."
Trixie gasped. "Teleport?! But...but that's advanced magic! I can't—"
"With these two helping you, I am confident you will learn," Celestia said. "And Twilight?"
"Y-yes, Your Majesty?"
"The next time you have a dinner party, you had better provide both dinner and a party."
"Of-of course, Your Majesty."
Celestia turned and left, her shoes clicking on the cold crystal. Twilight, Starlight, and Trixie turned to look at each other.
"Well...that was humiliating," Twilight said.
"Trixie is mortified beyond words," Trixie said.
"Would it be in really bad taste to gloat because you got in trouble with your mommy?" Starlight asked.
Twilight narrowed her eyes. "Would you like to spend all night cleaning the dining room by hoof?"
Starlight considered that. "Could be worth it," she said.
Twilight growled.
Trixie cleared her throat. "Perhaps...we should simply send the guests home and call it a night? Trixie always has wanted to spend the night in a castle..."