Eleven-year-old Penny Maxwell has anxiety and hates it. It stops her from speaking up in class, making friends, and sometimes even causes embarrassing panic attacks at the worst possible moments.

Rather than hanging out with other kids after school, Penny volunteers at the local animal shelter, where, surrounded by furry friends, she feels like she can be herself. While tending to the rescued pets, Penny has been secretly writing fanciful backstories for all of them, but hasn't shared the tales with anyone and never would.

But when her beloved safe space is suddenly under threat of shutting down, sharing them might just be the only solution, at least according to Ada, a precocious new friend who hatches a genius scheme for them to save the shelter together. Can Penny find the courage to face her anxiety and overcome her fears in time?