National Book Award finalist Laura Ruby and New York Times-bestselling illustrator Dung Ho bring us an unforgettable story of the many different ways in which families are made and the beautiful, unknowable, magical things that hold them together.

For as long as Molly can remember, it's always just been her and Dad. Dad, who likes to splash in the pool, who likes to spin at the park, who bakes the best cookies around.

But that was before Dad married Ms. Too. 

Ms. Too doesn't like to splash. She doesn't like to spin. And she can't bake anything.

"But Molly, you used to love Ms. Too."

That was before, when she was Molly's favorite librarian. Now everything has changed. 

But as Molly and Ms. Too are about to discover, maybe change isn't always scary. Maybe change can be the best thing of all.