House on Fire - Joseph Finder

Nick Heller, private spy, exposes secrets that powerful people would rather keep hidden. At the funeral of his good friend Sean, an army buddy who struggled with opioid addiction, a stranger approaches Nick with a job. The woman is a member of the Kimball family, whose immense fortune was built on opiates. Now she wants to become a whistleblower, exposing evidence that Kimball Pharmaceutical knew its biggest money-maker was dangerously addictive. Nick agrees instantly - but he soon realizes the sins of the Kimball patriarch are just the beginning. Beneath the surface are the barely concealed cabals and conspiracies: a twisting story of family intrigue and lethal corporate machinations.