Mission Improbable

In his imagination, he's still got a chance with Sarah 9 The Most Beautiful Girl in the World. In reality, she just wants to be friends. With no idea how to behave around her, it's time for Archie to escape the real world and prepare for a new level of geekiness - a weekend of costumed role-playing, complete with elf ears and foam swords.
Then along comes Clare, a girl with a foolproof plan. All Archie needs is a pretend girlfriend to make Sarah jealous and Clare is happy to play the part. But as their fake romance begins, Archie realizes that the idea is as doomed as a raid on a dragon's cave...