Mavis Jeeter is fearless and bold, but she has never lived in one place long enough to have a real best friend.

Her flighty mother has uprooted them again to another new home and taken a job as a housekeeper for the Tully family. Mavis wants this home to be permanent-which means finding herself a best friend.

Rose Tully is a worrier who feels like she doesn’t quite fit in with the other girls in her neighborhood. Her closest friend is Mr. Duffy, but he hasn't been himself since his dog died. Rose may have to break a few of her mother’s many rules to help Mr. Duffy-and find someone who really understands her. And then there's Henry, a dog that has run away from home.

But he craves kindness and comfort-and doesn't know where to look for them. When Mavis and Rose hatch a scheme to find Mr. Duffy a new dog, their lives and Henry’s intersect as they find friendship in places they never expected.