Katie Price is a 17-year-old girl who has lived her life confined to her home due to a rare genetic condition called xeroderma pigmentosum (XP), which renders her severely sensitive to sunlight. Spending her days indoors, Katie ventures outside only at night, where she can indulge in her passion for music by playing her guitar at the local train station. One night, she encounters Charlie, a young man she has secretly admired from afar for years. Unbeknownst to Charlie, Katie's nighttime outings are a necessity due to her condition. As they begin to spend time together under the cover of darkness, an enchanting romance blossoms between them.

Katie must navigate the challenges posed by her illness while attempting to live a normal life with Charlie. Balancing her desire for a deeper relationship with the need to protect herself from the sun, she faces difficult choices and heart-wrenching decisions. The story delves into themes of love, sacrifice, and the struggle to enjoy life despite its limitations. Through tender moments and heartfelt revelations, Katie and Charlie's developing bond is tested by the harsh realities of her condition. Katie is confronted with the consequences of embracing a love that could potentially bring risk and heartbreak into her carefully controlled world.