Bella has a bear named Arthur. Like other bears, he's soft and cuddly. Unlike other bears, Arthur knows karate and works tirelessly all night to protect Bella from monsters, dragons, slugs, and other things that lurk in the shadows.

One night, Arthur goes missing. Her mother, her father, and her little brother search high and low, but he is nowhere to be found.

Will Bella ever find him again? Or can she find a way to be brave all on her own?