Pinkie Pie was starting to get frantic. Her eyes darted left. Then they darted right. Then they darted left again. They had been doing this for the last two minutes. She would have continued to do this if it wasn't for a new detail making itself known. Out of the corner of her eye, she spotted a well-groomed tail slip behind the corner of a building not too far away from her. Her eyes darted toward the location in space that the tail had previously occupied. She knew that purple tail anywhere. Without a moment to lose, Pinkie darted toward the corner of the building and peered out into the street that the pony she was looking for had just gone toward.
When she saw what was beyond the corner, her heart sank. Today was a busy day for the Ponyville marketplace. The streets were packed with ponies going about their daily commerce lives. One pony that caught Pinkie's eye was offering half off for flour today. She made a mental note of this before reminding herself that she was on a question to find her lost cupcakes.
"Poor cupcakes", Pinkie Pie thought "they must be so lonely without me". Reminding herself that she had already wasted enough time thinking about this, she ran into the crowd before her in an effort to find the marshmallow pony that she was looking for. To her surprise, she found the pony she was looking for mere seconds later. In an effort to get to her faster by getting her to slow down, Pinkie Pie called out to Rarity, "Hey!".
Rarity didn't even look behind her when she started a mad dash forward and further away from Pinkie Pie. Pinkie Pie went ahead in pursuit. "Where are you going!", Pinkie Pie called "I want to know who took my cupcakes!" The chase was on and Rarity was far ahead of Pinkie but Pinkie was closing ground. The ponies around were not too happy about a pair of tail chasers running past them.
"My eyes!", cried one pony who had an open barrel of jelly get knocked on top of him by a careless Rarity. Another pony saw the two coming and panicked in the least productive way possible. Instead of getting out of the way, this pony ran directly forward in the direction the two mares were. He, however, was much slower. Rarity caught up very easily and crashed into him. Pinkie Pie, having only the singular focus of catching up to Rarity and forgoing situation awareness, quickly reached her goal soon after that and crashed into Rarity.
The random panic struck pony was quick to get up and run away frantically while all the while yelling, "Don't hurt meeeeeeee!"
Now that the chase was over, a very annoyed Pinkie Pie turned to Rarity and said, "Rarity! Who took my cupcakes?"
Rarity began to stutter a response, "I-I-I don't know Pinkie b-b-but it wasn-n't me". Pinkie Pie began to get really close to Rarity. She squinted her eyes and focused them very carefully into her friend's eyes and said "then why were you running from me?".
"I-I was scared by your sudden yelling and-and decided to run" Rarity was even more scared now than she had been during the persuit. Her legs were beginning to shake and she made a wish that someone would come to save her before the worst case scenario happened.
However, she did not need saving as Pinkie Pie snapped out of her stare even faster than she started it while saying, "Ok, I believe you. Have a super fantastic day Rarity". As Pinkie was hopping away from her friend she could have sworn she saw her faint. She didn't have time to turn around, however. She needed to find the next of her friends to see if they had the cupcakes. "Oh cupcakes, where are you my delicious cupcakes", Pinkie pie said and proceeded to sigh as she began to make her way over to a little cottage on the edge of the Everfree forest.