Twilight Sparkle had to use King Sombra's Dark Magic to solve various puzzles. She claims that Celestia showed her how, but how is she perfect at the spells at the first go? Something stinks of a nefarious plot....
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I hope everpony likes this! I had this idea after watching the Season Three premier, and it wouldn't go away until I wrote it! I'm sorry if the writing isn't up to your standards, but I'll appreciate and constructive criticism!
Also romance for eventual shipping.