When snow shuts down Greg Heffley's middle school, his neighborhood transforms into a wintry battlefield. Rival groups fight over territory, build massive snow forts and stage epic snowball fights. And in the crosshairs are Greg and his trusty best friend, Rowley Jefferson. 
It's a fight for survival as Greg and Rowley navigate alliances, betrays and warring gangs in a neighbourhood meltdown. When the snow clears, will Greg and Rowley emerge as heroes? Or will they even survive to see another day?