When the Cutie Map summons Fluttershy and Pinkie Pie on a mission, they're surprised when it's in Ponyville.
Only, there doesn't seem to be any ponies in need of friendship help - just reports of a strange cat and mouse chasing each other...
My entry into the Who Crossed Over With My Little Pony? Contest
Rated T for Slapstick and General Cartoon Violence that comes with a cat chasing a mouse.