It was rare that she could sleep in, and Twilight Sparkle was making the most of it; she determined that this would be a lazy Sunday, with no unusual happenings that would force her out of the bed now that she had discovered a position which sent her tired body rocketing toward fresh paroxysms of comfort and snugness. Even her wings weren't bothering her for once; they had folded themselves neatly along her sides, and hadn't sprung haphazardly out of position once during the night. The covers felt feather-light, and there was just enough coolness drifting in from the partially-open window to take the edge off a balmy spring morning; the mattress softly hugged every contour of her body, but was firm enough to support her spine without putting any undue pressure on her enervated joints.

Predictably enough, it was at this point that there came a soft rapping at the door. “No!” Twilight screeched irritably – the harsh knocking sound cutting into a rather pleasant dream she had been having involving an army of Flash Sentrys and their creative uses for a barrel of lavender oil – pulling the pillow over her head and hoping that whomever it was would soon get the message and leave.

No such luck. The dull thumping began to get louder, and an agitated voice was calling her name over and over. Even through the impediment of the thick, fluffy pillow, the lavender-coated pony guessed that it was one of her friends. She hoped so: anyone else rude enough to drag her out of bed on her one day to relax would never have the opportunity to annoy anyone again.

It was probably important, Twilight decided, grumpily getting to her hooves and brushing her mane into some semblance of order; after throwing some water over her face so she wouldn't look too groggy, she walked over to the front door and opened it …

… and was assailed by a frantic pink missile.

Who else but? Twilight thought wearily, sensing any chance of crawling back under the covers for an hour or two evaporating instantly. “Good morning, Pinkie, what can I do for you?”

“Twilight?” Pinkie questioned, a confused look on her face. “You look different.”

“In what way?”

“Uh, a bit more horizontal?”

“That's because you knocked me to the ground when you barged in and,” she gestured with her head, “you are standing on my shoulders so I can't move.”

“Oh,” the party pony replied distractedly. “Does it hurt?”

“Let me think … yes!” Twilight answered sharply.

“I should move?”

“If you wouldn't mind.”

With an air of supreme distraction, Pinkie Pie moved aside, allowing Twilight to get to her hooves. She dusted herself down and stretched the kinks out of her tired muscles. “So. What can I do for you, Pinkie?” she finally asked, trying not to be too angry with her friend. The pink pony was about the sweetest soul in Ponyville, but her mind could be rather … monomaniacal at times, and it was difficult to explain things to her when her attention was focused elsewhere. As it was at the moment. “Pinkie, what's wrong?” Twilight asked again, with an edge of concern beginning to creep into her voice. She'd never seen her friend look so agitated before. Not even when they'd tried to keep her birthday party secret from her.

The pink pony stopped hyperventilating and stuck her tongue out while rifling through her bouffant hair until she struck upon the item that she wanted. It was a piece of paper, and for a second, Twilight wondered what it contained that had caused Pinkie to react the way she had. “Is it bad news?” she hesitated. Oh, Celestia, it could be test results from hospital, or news about a family member, or … who knows what?

“Just look at,” Pinkie said, distress evident in her voice.

Twilight took the paper and scanned it quickly, looking for phrases like we regret to inform you or condolences or anything of that ilk. “Milk, eggs, butter …” Realisation dawned. “Pinkie, this is a recipe for a cake!”

“I know.”

“Then, why has it got you so flustered?”

“Look at the final ingredient.”

Confused, the lavender alicorn did so. “Artificial sweetener?”

“What the heck is that?” Pinkie demanded, her eyes practically bulging out of her skull. “I know every ingredient to every cake, and I've never once heard of this artificial sweetener. I've asked around. No one stocks it. No one's even heard of it. What's so funny?”

At some point during Pinkie's rant, Twilight had collapsed to the floor – her swings spreading out just in time to cushion the blow from the hard floor – and was presently laughing her head off. Regaining some semblance of control, she wiped the tears out of her eyes and stood up. “Artificial sweetener is a pony-made alternative to sugar,” she explained, switching easily into lecture-mode. “It's usually for ponies on special diets – either because of an illness like equine metabolic syndrome or they just want to manage their weight – although some ponies just prefer the taste. While I accept it's not something you're likely to come across too often, I don't understand why it made you react the way it did.”

“How did I react?” asked Pinkie, her eyes wide.

“Like the world was about to come to an end.”

Pinkie Pie shook her head before a broad grin broke out on her face. “Guess I was overreacting slightly, huh? It's just that, well, I pride myself on knowing everything there is to know about baking, and to discover that there's something I don't know is a bit of a shock.”

Twilight remembered all the times where she had taken her studies too seriously, or had overreacted to mundane problems – such as being late with a friendship lesson for Princess Celestia – and it was easy to look back and say that they were trivial matters, but at the time, they felt like the most important events in the world. “I know exactly how you feel, Pinkie,” said the lavender pony finally. “You can't know everything, though, and I don't think you'd want to either. The joy of making new discoveries is so thrilling and there are very few feelings that match it.”

“I have to get this cake baked by tonight, so will you help me find sweetener somewhere?” Pinkie asked. “That can be your new discovery of the day,” she added with an ingratiating smile.

Twilight thought for a moment. The market at Canterlot would probably have it; the stores there were used to catering for a wide variety of tastes, and so their selections tended toward the eclectic. Still, the crisis hadn't taken nearly as long to resolve as she thought, and her bed looked so inviting, with its snug duvet and fluffy pillows, and its promises of enticing dreams. For a moment, she was tempted to send Pinkie on her way.

But she couldn't really ignore those puppy-dog eyes. Could she?

“Give me a minute to get properly ready.”

“Okie dokie lokie.”