Sophie must confront her past and her complicated feelings for Angelo to secure her future and the marriage she desires. Sophie has long avoided the influential Marchese family, but circumstances now force her to seek their financial aid to marry Mark. Her only recourse is to call upon a promise made years ago by her stepcousin, Angelo, a promise tied to a glass unicorn. Angelo, a man of his word, agrees to grant her wish, but only if she truly knows what she wants. As her talisman, the unicorn, returns to Angelo's possession, its power begins to affect both of them in unexpected ways, complicating Sophie's objective.

The narrative appears to focus on a classic romance trope where a past promise and a symbolic object intertwine with the protagonist's present desires. The premise suggests a story rich in emotional conflict, as Sophie navigates her feelings for Angelo while pursuing her intended marriage to Mark. The presence of the Marchese family and the magical element of the unicorn hint at a potentially layered plot, blending romantic tension with a touch of the fantastical. The story likely explores themes of self-awareness and the true nature of desire.