It's a stormy summer day when Ottawa coroner Dr. Cate Spencer is called to the scene of an alleged suicide. Inside a narrow vault in the Dominion Archives' nitrate film storage facility—kept separate from the rest of the collection due to its dangerous combustibility—officers pressure her to rule the death a suicide. When parts of the scene don't add up and a deliberately set spark threatens her life, she suspects that this death might be a murder. Her tough façade masks a deep compassion for the victims she examines. Whether she's looking for answers because of her dedication to justice or to distract herself from anguish over her brother's recent death, her inquiries plunge her into a world of military secrets, contentious Indigenous protests, and a seventy-year-old mystery with deadly implications. Will Cate manage to pull herself away from her scotch and grief to expose an explosive historic secret and solve a murder the police doubt even exists?