It began with an email. Colin Kahl, who served as an advisor to then-Vice President Joe Biden, had been out of government for a few months when a woman identifying herself as Adriana Gavrilo reached out to inquire about his daughter’s school.

What followed was an ordeal that seemed to be connected to Kahl’s work on the 2015 Iran nuclear deal—and efforts by certain people to undermine it. Kahl, a co-editor of Foreign Policy‘s Shadow Government channel, tells the story.