On a warm August day in 2004, Eric McDavid was sitting inside a house near Des Moines University in Iowa, talking to Zach Jenson, a guy he’d just met, about life as a roving environmental activist. McDavid was 26, Jenson 19, but Jenson was much more experienced—he’d already taken part in loud but uneventful demonstrations that summer at the G8 Summit, an economic forum for the world’s industrialized powers held on Sea Island, Georgia, and at the Democratic National Convention in Boston.
Both men were in town to attend the third annual CrimethInc, an invitation-only gathering for anarchists and anticapitalists eager to share ideas about political organizing. (The name is a play on “thoughtcrime,” from George Orwell’s 1984.) Roughly 15 people who were in town for the event were staying in the same group house.
The phone rang. It was a woman Jenson knew named Anna, who said she’d hitchhiked from Florida and needed a ride in from a truck stop. Jenson, McDavid, and a few others drov...