Every Saturday, Pawcasso trots into town with a basket, a shopping list, and cash in paw to buy groceries for his family. One day, he passes eleven-year-old Jo, peering out the window of her house, bored and lonely. Astonished by the sight of an adorable basket-toting dog on his own, Jo follows Pawcasso, and when she’s seen alongside him by a group of kids from her school, they mistake her for Pawcasso’s owner.

Excited to make new friends, Jo reluctantly hides the truth and agrees to let "her" dog model for an art class the kids attend. What could go wrong? But what starts as a Chihuahua-sized lie quickly grows Great Dane-sized when animal control receives complaints about a dog roaming the streets off-leash. With Pawcasso’s freedom at stake, is Jo willing to spill the truth and risk her new friendships?