Popular author Aventurine Morrow brings her nephew Paul on a research trip to York, England, where she intends to interview an elderly WWII spy for her next book. Paul, grief-stricken over the death of his father at sea, wishes to visit the Machina's last port of call. As the two travel together, hints of Aventurine's past begin to darken their steps, until long-hidden family secrets are brought out into the open through the interference of Aventurine's former lover—secrets that threaten to destroy the relationships she's built with friends and family alike.