It’s a celebration of imagination, and the scope for it that a small boy finds playing outside on a snowy day.  While big brother sits inside, watching TV and playing on the computer, little brother heads outside to play in the snow.  The illustrations share with the reader the wonder of the boy’s imaginings as we see a snow-covered tree take the shape of a friendly snow-monster, the snow-monster he makes come to life and play with him in his snow castle, until he flies home on the dragon of the sunset, only to find his brother finally ready to come play with him in the snowy dusk.