The adventures of a little boy in the city on a very snowy day.

When Greg Heffley's school closes because of heavy snowfall, the neighborhood becomes an icy battlefield: rival groups compete for territory, build forts and stage big snowball fights. In their struggle for survival, Greg and Rowley will have to fight their way through alliances, betrayals and opposing gangs. When the snow melts, will the two friends get out alive from this pitched battle?