When Lily and Max discover a magical garden wilting by the river, they enlist their friend Emma and a wise turtle to uncover and solve the mystery of the blocked water.
A young girl named Emma, with a unique ability to make people see the goodness in others, leads a divided Washington DC towards unity and acceptance despite the efforts of the antagonist, Otto.
After discovering they must swim without floaties, Grace and Cooper bravely face their fear, learning new skills and gaining confidence with the help of friends.