Tector, Amy. Dominion Archives mystery.

"It's a steamy summer Ottawa day when Cate is called out to the nitrate facility to investigate an apparent suicide. The eerie building is filled with deteriorating nitrate film that could literally spontaneously combust. When Cate's life is threatened by a stray spark, she suspects that the suicide might be murder. Despite pressure from the police to pronounce on cause quickly, Cate is bloody-minded enough to keep investigating. Whether she's looking for answers because of her dedication to justice, or as a distraction from the grief she feels 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"--