It is a sunny, lovely day in Rivervale, or at least as lovely as a day can be when it involves sitting in school all afternoon. Fortunately, school is over, and Amity can forget about the worksheet currently sitting in her backpack, or at least pretend for a little while that it does not exist.
As she heads home from the bus stop, she notices something odd in the sky. There is a large, fluffy cloud drifting over the treetops, except it does not seem to be drifting in quite the right direction. The breeze is carrying the other clouds one way, while this one is slowly moving in the opposite direction.