What: Sneak attack.
When: Afternoon (We're still working a month ahead, right? So snow in December is acceptable)
Why: Because Jon looks funny when trying to get snow out of his ears.
Julie had been poised behind the statue of Idris Oakby for twenty minutes now. Her tennis shoes were not conducive to the cold weather, and though she had cleared away a small patch of snow, her toes were still freezing. The hand that wasn't holding a snowball was wedged deep into her pocket (around her wand, just in case), trying to keep warm. She wouldn't have been able to tell you how the hand holding the snowball felt because she had lost feeling in it about ten minutes ago.
She glanced at her watch. Ten minutes late at least. Julie nearly let out a curse, nearly gave away her position, before spotting her target hurrying down the stone steps, bag bursting with books and quills.
She took aim. Pulled back her arm. And threw. The snowball hit Jon square in the jaw.