Mab is the eldest of the Mitchell triplets. She describes an essay assigned by her history teacher in which students are tasked with narrating their first memory. She chooses her birth as her topic and writes that even in the womb, she and her sisters were together. She is the first to be born, while Monday comes second, and Mirabel is third. The girls assign themselves the nicknames “One,” “Two,” and “Three,” each using the number that corresponds to the order in which they were born. Doubtful that Mab can remember her own birth, her teacher scolds her for her choice of topic, noting that she “asked for an essay, not a short story” (2).

On a rainy summer day, Monday takes a cereal box, glue, scissors, a ruler, and all of her green colored pencils to the upstairs hall closet. Anticipating her mother’s imminent return from work, she quickly and precisely cuts out a postcard from the cardboard, decorates it with trees, addresses it to Mab, and slides it under their bedroom door. Mab tacks it up onto the wall, where it joins the 246 other such postcards that Monday has crafted.