Nancy and Bree are searching for a butterfly with no luck. Bree decides to keep looking, and Nancy finds a butterfly in a fountain. They think it's exquisite, and Nancy assumes that she came to play with her. Nancy knows about butterflies, and decides to dry the butterfly's wings after scooping her from the fountain. After Nancy scoops the butterfly out, she calls her Papillon. They bring the butterfly home, where the Clancys are building a marshmallow tower.
Nancy and Bree then head upstairs, and Bree suggests the butterfly get some rest. Nancy rests the butterfly on Marabelle's bed, and decides for her and Bree to dress up as butterflies. Nancy decides for her and Bree to make a house to protect the butterfly's wings, and meanwhile, Frenchy ate the last marshmallow, which the Clancys need to finish the tower. As Claire searches for something, Nancy arrives and tells her what she and Bree are doing.
Nancy and Bree then finish the house for Papillon, who needs a little quiet time. JoJo then arrives, reminding Bree of her piano lesson. Nancy will take care of the butterfly, who wants to play with her. Nancy wonders what things would be like when Papillon can fly again. She then begins to fly, and dies so all over the house. Nancy tells the situation to her family, and closes the door right before Papillon escapes. She then returns to her home, and Doug chases JoJo away while deciding on a velociraptor to play with.
Claire thanks Nancy for her and Bree helping Papillon get better. Nancy decides to attend something, and she reunites with Bree outside. Nancy then recites a poem to say goodbye to Papillon, who starts to fly, as she's all better. Papillon then flies away, and Nancy and Bree decide to fly free like Papillon.
