In the small, rain-soaked town of Port Haven, every resident carries a physical manifestation of their past regrets—a tangible object that appears on their person at the moment of a deeply remorseful decision. The series follows Jodie Comer as Maya, a grief-stricken archivist who arrives in town hoping to leave her own heavy burden behind, only to discover that the community is bound by an ancient, unspoken rule: these "yesterdays" can be transferred from one person to another, but never destroyed. As Maya befriends John Boyega as Leo, a local fisherman desperate to shed the memory of a maritime tragedy, and Sandra Oh as the enigmatic town elder Hilda, who claims to know the origin of the curse, a deeper mystery begins to unfold. The central conflict emerges when a stranger arrives with the ability to forcibly extract yesterdays, threatening to shatter the fragile balance of the town. Blending atmospheric mystery with poignant character drama, the show explores themes of forgiveness, communal guilt, and the weight of choices in a world where the past is literally carried on one's back.