Mattie Arden has just escaped from a toxic relationship so when she receives a letter informing her that she has inherited a house from her great aunt Millie a few days before Christmas, it's a welcome distraction. Except it comes with a strange proviso: if Mattie wants the house, she must fulfil Millie's last wish and scatter her ashes over "the boys of Christmas". In the company of her best friend Toby, Mattie sets out for the seaside village of Christmas Steepleton in the hope of finding out the meaning of her aunt's bizarre request.