That point was driven home in startling fashion when we recently reported that the Massachusetts attorney general had accused McKinsey of fanning the flames of the opioid epidemic. In legal papers, the attorney general alleged that McKinsey had instructed the maker of a powerful opioid on how to “turbocharge sales” of the drug, how to counter efforts by drug enforcement agents to reduce opioid use and how to “counter the emotional messages from mothers with teenagers that overdosed” on the drug.

Despite McKinsey’s refusal to allow its employees to speak freely with us, we managed to contact and interview 44 current and former McKinsey employees around the world, often using encrypted forms of communication. As part of our research, we traveled to South Africa, Ukraine, Austria and Guernsey in the Channel Islands.

Michael Forsythe, who has reported extensively in China, used his deep knowledge of that nation’s government, language and social media to help build a custom database tracking McKinsey’s work in that country. As a result, we were able to report that McKinsey had advised 22 of the 100 largest state-owned enterprises, including one that built the artificial islands in the South China Sea, a major point of military tension with the United States.

Just one week after the United Nations denounced the mass detention of thousands of ethnic Uighurs in a vast archipelago of indoctrination camps, McKinsey chose to quietly hold its annual corporate retreat nearby. We not only reported on that retreat, in Kashgar, China, we also published pictures of it, including one that showed red carpets winding through the desert. Under the headline “How McKinsey Has Helped Raise the Stature of Authoritarian Governments,” we also documented the firm’s work in Russia, Ukraine and Saudi Arabia. McKinsey’s work in these countries is noteworthy because it comes at a time when democracies around the world are under attack.

Much of our reporting relied on McKinsey’s own words, memorialized in a medium the firm has mastered: the PowerPoint slide.