Knuckles

>*pak*
>Twilight jerks at the noise, sharp in the otherwise silent library.
>You flip to the next page of the book you’re reading. Something mildly interesting about the history of magic.
>Having the book the table to free up your hands, you distractedly reach for the middle finger of your left hand with the thumb and index finger of your right.
>Bending the finger ever-so-slightly backwards at the knuckle, it cracks.
>*pak*
>Twilight stares.
>Apparently Starswirl the Bearded created some sort of perpetual motion device and used it to power his washing machine.
>You repeat the knuckle-popping process, not really paying attention to what your hands are doing.
>*pak*
>When the washing machine was disassembled after his death in an attempt to reverse-engineer it, the thing spun violently out of control and shattered.
>*pak*
>The force propelled shrapnel over a 4-mile radius. Even today, ponies in that area are still finding bits of scrap metal in their lawns.
>Having cracked all four of your finger-knuckles, your right hand moves to your thumb, pressing it down into your other palm.
>*pok*
>”Doesn’t that hurt?”
>Twilight’s brow is furrowed, and she’s frowning.
“Doesn’t what hurt?”
>”That thing you’re doing to make your hands pop.”
>You blink twice, slowly.
“No.”

>”it’s really creepy. Are they even supposed to bend like that?”
“Not usually, but it’s fine.”
>*pok*
>She winces as you pop the knuckle of your right thumb.
>”Could you not do that?”
“There’s 4 left. I can’t leave half my knuckles uncracked, it’ll feel weird.”
>*pak*
>She winces, again, and her ears flatten against her head.
>”Can you at least hurry it up?”
“Sure, I guess.”
>You press the remaining three fingers down into your palm.
>*PAK*
>”Are you done with the horrible finger noises?”
“Yeah.”
>You both return to your reading.
>Starswirl powered his clothes-dryer by transferring waste heat from the perpetual motion device.
>When the washer exploded, the drier burst into flame and burned down his house.
>Vast amounts of magical knowledge was lost in the unfortunate blaze.
>All because an incredibly powerful wizard couldn’t be arsed to do his laundry manually.
>You bend your neck to the side, almost touching the back of your head to your shoulder, and your spine cracks.
>*puk*
>And that is how you got banned from Ponyville’s library.