The story begins with a heartwarming tradition: Grandmother visits Polly and Betty on her birthday, bringing with her "two packages" that contain "magic." Upon opening these packages, the girls discover two flower pots filled with "black dirt," each accompanied by three letters tied with strings. These letters serve as a guide for the girls to unlock the mystery of the magic, with instructions to be opened in specific intervals: immediately, four weeks later, and on Valentine's Day. Grandmother emphasizes that if they follow these steps, the pots will eventually provide a "big surprise."
Following the first set of instructions, the girls place their pots in the "dark place in the cellar." Four weeks later, the second letter instructs them to provide water and, if they see any signs of magic, to move the pots to a "north window." Betty is the first to witness the results, discovering a "tiny plant" emerging from the soil. Through research in a book about flowers, the girls identify Betty’s plant as an "Easter lily." By Easter, Betty’s plant flourishes with "five pretty white flowers," showcasing the success of her patience and adherence to the instructions.
In contrast, Polly experiences a period of disappointment as her pot remains empty. Despite the lack of growth, Polly maintains her belief, stating, "Mine is a magic pot, too," and continues to nurture it in the "warm sunshine." Unbeknownst to her, Father had secretly planted "garden seeds" in her pot to replace the failed lily. Soon, a green plant emerges. While Mother notes it is "not a lily," she encourages Polly, promising that her magic pot will yield a "big surprise." As the plant grows too large for the pot, Father transplants it into the garden, where it continues to expand, eventually producing "big yellow flowers" and a massive "green ball."
As the green ball grows larger—eventually becoming "bigger than father's head"—it finally turns yellow, and Polly realizes it is a "fine, big pumpkin." Recognizing the perfect opportunity, Polly decides to turn this unexpected harvest into a "pumpkin pie" for Grandmother’s next birthday. When Grandmother returns, Polly presents the pie, playfully claiming, "Here is my Easter lily." The grandmother, delighted by the clever twist, laughs and remarks, "That was the best Easter lily I ever ate."
This narrative beautifully illustrates that magic is not always found in the expected outcome. While Betty’s pot followed the traditional path of an Easter lily, Polly’s journey taught her that even when things do not go as planned, persistence and care can lead to a different, yet equally rewarding, "big surprise." The transformation of a failed flower into a delicious pumpkin pie serves as a charming metaphor for finding joy in the unexpected turns of life.