Life isn't always easy when you're the only repairpony for enchanted devices and conveniences in all of Ponyville. It can get rougher when you're exactly the wrong race for the job...
Most folks in town know about Longbow, even if not many really know her. She's somepony parents teach their foals to avoid. Everypony understands that she's dangerous. Everypony except Twilight, who just moved to town.
Dust has lived on the edge of Ponyville all her life, keeping to herself and studying. When she makes a big discovery, she's eager to run to the castle and spread the good news! But why don't the ponies of Ponyville seem happy to see her?