The True Rainbow Dash: A changeling story

I couldn't figure out how to do it by myself... So I decided to steal a book from Twilight's library about changelings. It was quite easy considering she fell asleep while studying which meant she hadn't locked the library's door. I hate reading anything but Daring Doo books but I don't really have a choice. At least, the book was easy to understand, in about an hour I was able to easily look my normal self again. I also read a bit about how to shapeshift into other ponies. It may be quite useful in case of emergency but I really hope I'll never EVER have to use this ability...