Derpy smiled at Twilight Sparkle.

Twilight Sparkle smiled back and floated a stack of letters toward the mailpony with the pink glow of her magic.

"Sorry, Derpy."

Surrounding the two ponies who stood just outside the Golden Oaks Library was a beautiful spring morning. A few clouds drifted lazily above, birdsong twittered from the living branches of the giant tree that housed the library's interior, and Market Square absolutely bustled with the activities of ponies going about their daily business just out of earshot.

Derpy's ears drooped, but her characteristic smile stayed locked in place. "They're not yours? Are you sure?"

Twilight turned the sealed letters in midair so that Derpy could read them. "Yes, unless my name got changed to 'Hugh Jelly' sometime last night."

Taking the letters back in hoof, Derpy looked over them for a second longer than Twilight thought necessary before her somewhat dopey smile turned down a little. "Gee, I'm sorry, Twilight," she apologized as she tossed the stack back into the saddlebag on her left side and began rummaging through one on her right. "I really worked hard to get everything sorted this morning. I was sure I had it right this time."

Derpy's throat clenched painfully as she nosed through the various parcels. Mistakes like these demanded that she think about their cause, and she never liked to think about her job. She'd meant to sort the letters properly this morning, just as she'd meant to every other morning. Despite her efforts, every day came with more mistakes than the last.

"I wish I could say, 'that's okay,'" Twilight conferred in a gentle tone of voice, "but I really don't appreciate having to come out here every day and double-check your deliveries. Are you—" She paused, her violet eyes glancing left and right. "Are you sure that being a mailpony is a good use of your talents?"

Derpy pulled an encyclopedia-sized box from the saddlebag and turned back to Twilight with a strong and decisive movement. As Derpy allowed the package to leave her grip by way of Twilight's magic, she gave her bold answer in the form of a question. "What does that tell you?"

Twilight inspected the information on the package for a moment before looking up from it with an arched eyebrow. "That Mr. Cake is getting the replacement part for his busted mixer today." She turned the box around as Derpy's mouth dropped open. "It's even got the Sugarcube Corner logo printed right next to the delivery address."

Derpy fumed inwardly and fought to keep her facial expression cordial. "Sorry, Twilight," she sighed, though her mind played host to a mix of potent humiliation and impotent anger. She wanted very much to read about Daring Do's latest adventure and forget about this embarrassment. Even the knowledge that she'd read all those books did nothing to quell the desire.

Derpy leaned forward to retrieve her second mistake from midair. The motion was heavy and slow, too slow to stop a bouncing pink pony with a fluffy mane from plucking it away like a piece of low-hanging fruit.

"Ooh! It's finally here!" Pinkie Pie exclaimed as she twirled the package around like a dance partner. "Now I can start mixing things up again!"

Twilight chuckled at her friend's oddly-timed appearance. "I think you two have that market cornered, with or without the repair kit."

"Derpy's not a baker, Twilight," Pinkie stated matter-of-factly. "Did you go silly in the head from too much bookifying?"

Derpy felt a smile returning to her lips as the lump in her throat subsided. She plunged her muzzle into the depths of the right saddlebag for the third time.

Twilight rolled her eyes. "You're the one who's being silly, Pinkie. Sugarcube Corner has three industrial-grade mixers; all of them would have to break before you stopped mixing."

Pinkie waved a dismissive hoof at her friend and flashed a toothy grin. "Yeah, but Mr. and Mrs. Cake only let me use the one that breaks all the time."

Twilight's brow furrowed. "I'm sure that's a coincidence."

"Speaking of coincidences," Pinkie exclaimed, turning toward Derpy with an even more brilliant smile. "You are—like—the best mailpony ever! How did you know I was gonna walk by just now?"

Derpy nearly lost her grip on a couple of freshly-retrieved letters as she turned to face Pinkie with wide eyes. She'd never been called that before. Come to think of it, she'd never been called anything before . . . at least, not positive.

Pinkie Pie's gaze narrowed. "Do you have a 'Derpy Sense?'"

Twilight gently pushed Pinkie aside and eyeballed the letters. "Actually, I think she's got my mail."

"Oh well," Pinkie Pie remarked, tossing the repair kit onto her back with a carefree motion. "It's a mystery for another day. Thanks, Derpy!"

Twilight watched her friend bound off in the general direction of Sugarcube Corner before turning back to find a grinning Derpy, each of her two eyes looking at something that wasn't Twilight. She leaned forward and took hold of her correspondence.

"Best mailpony ever . . ." Derpy Hooves repeated in genuine awe.

Twilight bit her lower lip, but her words came out strong in the next moment. "We both know that was luck, Derpy. If you had the kind of talent that Pinkie's talking about, you wouldn't be making mistakes in the first place."

This time Derpy couldn't help but look crestfallen. The mailpony lowered her head in shame only to see a lavender-furred hoof reach over and touch her own.

"Listen," Twilight said, her voice growing softer and venturing down an octave. "If you're in love with the idea of delivering Ponyville's mail, then I've got no right to criticize your choices. I'm just worried that you're sinking all your time and effort into something that you're not suited for."

Derpy didn't raise her head.

"Even if there's some other kind of problem behind this," Twilight continued. "You know that you can ask for help anytime you need it, right?"

Derpy's head snapped back up in an alarming fashion, her left eye fixed directly on Twilight. "Uh-oh."

Twilight Sparkle cocked her head to the side. "What's 'uh-oh?'"

Derpy gulped. "I forgot something."

LL