Twilight nestled deeper into her blankets, the rain tap, tap, tapping her window so insistently, like Rainbow Dash when she wanted to tell her something. Twi poked her head out the window. She had been Dash's marefriend for long enough to know that if the storm seemed to be telling her something, it probably was.
She squinted and saw a small cyan shape darting through the clouds, the lightning occasionally lighting up her form. She smiled. She loved it when Dash put on a performance out there in the rain just for her. All the weather ponies needed to do was set up the thunderheads, let them run their course, then come back out to clear away the stray bits of cloud. But Rainbow insisted on performing for Twilight during the storms, both because she liked feeling like a demigod and because she liked striking a wet-mane pose when she came back to the library.
The storms were Rainbow's art, and the sky her canvas. She would often draw the lightning toward her to make designs, or kick the thunderclouds to make a sort of wild music. It was a breathtaking, heartstopping, artistic sport, and Rainbow reveled in being the only pony with the guts to play it.
Twilight clapped at every lightning bolt and cheered at every thunderclap. True, she didn't have enough skill as a flyer to play Rainbow's game with her, but she would be darned if she wasn't Equestria's best cheerleader.
Eventually Rainbow would get tired and touch down, running toward the library. And she would even make that a show, leaping over carts instead of going around them, landing in the puddles in certain ways to make the perfect splash. She slammed one hoof against the door loudly, too tired and exhilarated for a proper knock. Twilight hustled downstairs and opened the door, where Rainbow had struck a pose for her. Twilight laughed. "Come on in."
Rainbow stepped in, gratefully taking the towel she offered and drying herself off. Twilight went and made Rainbow some coffee, which she accepted when she finished drying off.
They both sat there for a while, contented in each other's company. "Hey, Twilight?"
"What is it, Dash?"
"Thanks."
"It's no trouble. Only you can make a storm a work of art."