One final check worth making is to ask yourself: "Is there any way I have identified my confidential sources, even though I promised to keep them secret?
Your material is longer and more complex than a typical hard news story and giving it shape and structure gives your readers a pathway through complex information.
You are not creating fiction, but you are employing techniques from literature.
At best, stories like these are boring; at worst, they are impossible to understand. Societal trust? Talk only about the facts you need to know for your story.
These will add variety and also act as confirmation. Once inside, he takes every opportunity to prolong his visit, including accepting offers for coffee and, if he needs to, using the bathroom.
Organizing and writing the story can be the key to an exceptional investigative report. Someone - probably the people your story exposes as corrupt, dishonest or simply incompetent - will be looking closely for mistakes to attack you on. Be very careful when covering any sub judice matters.
Lost in the Storm Sheri Fink, The New York Times Magazine I am going to use this opportunity, which Longreads has graciously and somewhat surprisingly granted me, to share another gut-punching narrative investigation.
Always ask yourself: Does this add value or merely extra words? You need to explain who is hurt. This does not devalue the narrative approach.