Forest Lost’s introduction presents the book’s focus on efforts to make the living forest and its carbon valuable in the Brazilian Amazon. Forest carbon is a strange commodity, the introduction suggests, because it requires not the extraction entailed in the production of many other tropical forest commodities but rather that forest carbon be held in place in the living forest. Forest Lost centers on the relational work required to keep that carbon in place. The introduction presents this relational approach, as well as the contested social inclusion and apparent contradictions of green capitalism that come into view through it. It also introduces the state of Acre, Brazil, which is the book’s primary ethnographic focus, and discusses the Amazon as a resource, environmental, and imaginative frontier.