The theory of the sonic rainboom having something in common with a pony's mane color had been asked a few times, but who could match the incredible speed of Rainbow Dash to answer this? one pony by the name of Shadow Zipper appears in Ponyville in search of Rainbow Rash! Will this darkly imaged pony steal the rank of Equestria's fastest flyer, or will he turn out to a pretty nice guy? Follow his story as he meets new friends and embarks on a mission to create a different kind or rainboom!