In 1935 England, thirteen-year-old Briony Tallis witnesses an event involving her sister Cecilia and her childhood friend Robbie Turner, and she becomes the victim of her own imagination, which leads her on a lifelong search for truth and absolution.

Forest fires are reducing chunks of the Boulder Valley to tinder and ash; Colorado clinical psychologist Alan Gregory's colleague and close friend, still recovering from a terrible trauma, appears to be approaching a psychological breakdown; and new evidence in an old case causes Alan to reexamine decisions he made in the past, putting his entire career at risk.