Clare and Sara are sisters; Sara is cool, and Clare is not. Sara's boyfriend gave her a frog that she doesn't want, so she passes it along to Clare. Clare reluctantly accepts -- only to learn that the frog can talk, his name is Mazefield, and he wants to bring about the apocalypse.
So they make a deal: Mazefield will find Clare a date for the school dance, and Clare will meet with two foreign spies for Mazefield and report back to him. Both bungle their missions. Mazefield can't find Clare a date, and Clare accidentally invites the foreign spies to the school dance. It all comes to a head at the dance in an unexpected and heart-warming conclusion.
Part of the collection Keen Teens: Volume 3