The story begins with a heartwarming initiative by Polly, who wonders, "Why can't dolls have a Thanksgiving dinner like real people?" With her mother’s encouragement, Polly embarks on the meticulous task of preparing the dollhouse. She demonstrates great care by sweeping and dusting the house, setting the table with her "very best dishes," and adding a "tiny bowl of pink flowers" as a centerpiece. The attention to detail is evident as she places a "wee napkin and a cup and saucer" for each doll. Polly dresses her dolls—Sally in blue, Molly in pink, and Betty Jane in yellow—and gives them playful instructions to be careful with their attire, setting the stage for a festive celebration.
Polly’s mother contributes to the event by bringing in the "dolls' Thanksgiving dinner." The menu is charmingly miniature: each doll receives a plate filled with "turkey and other good things," accompanied by "wee cups of cocoa," a "tiny cake," and the "smallest pumpkin pie you ever saw." Polly leaves the dolls with a final affectionate gesture, kissing them goodbye before heading downstairs to join her family’s own Thanksgiving gathering. This transition highlights the contrast between the human-sized celebration and the imaginative world Polly has created for her toys.
Downstairs, Polly enjoys the company of her parents and their guests, particularly delighting in a man who performs tricks with napkins, transforming them into a "funny pig" and a "little rabbit." However, Polly’s thoughts soon return to her dolls. Upon returning to her room with her family, they discover a shocking scene: the dolls remain in their positions, but "nearly all the dinner had been eaten." The evidence is everywhere, with "crumbs on the plates and all over the table," the bread and cake missing, and a portion of the "tiny pie" consumed. Polly’s father expresses genuine surprise, remarking, "I didn't know that dolls could really eat."
The mystery is quickly solved when the culprits reveal themselves. A "squeak" emanates from the dollhouse, and a "little gray mouse" peeks out from beneath the table before darting away. Further investigation reveals a second mouse under a chair and a third hiding "beneath the bed, with his thin gray tail sticking out." The mice appear to have thoroughly enjoyed the feast, looking as if they had "eaten a big dinner."
The story concludes with a moment of gentle wisdom. When Polly’s mother asks, "Shall I get the cat?" to deal with the intruders, Polly’s father intervenes with a compassionate perspective. He suggests, "Why can't poor mice have a Thanksgiving dinner, too?" This ending transforms the narrative from a simple tale of missing food into a lesson on kindness and empathy, suggesting that the spirit of Thanksgiving—sharing a meal and offering hospitality—extends even to the smallest, most unexpected visitors.