Emerald (Em) has harbored a deep love for Ace, her brother's best friend, rooted in his childhood promise to marry her "when she blooms." Her world shatters at fifteen when she witnesses Ace kissing her sister, Tess, leading her to move to New York. Seven years later, Em returns to California with her kind but unloved boyfriend, Warner, for her siblings' engagement. She discovers Tess is marrying Ace's cousin, Caleb. Ace, now a powerful businessman, re-enters Em's life, displaying possessive interest, sending gifts, and orchestrating her job transfer to his company, effectively trapping her. He reveals he remembers his childhood promise, declaring Em "mine." Grappling with past heartbreak and confused by her lingering feelings, Em decides to confront her fears and stay for three months, despite her unreciprocated relationship with Warner.
