Near midnight, a group of six Guajajara tribesmen with their faces painted for battle listen to the rumble of heavy trucks about 19 miles (30 km) from their village in the Amazon rainforest.
They suspect a caravan of illegal loggers felling trees on their reservation. The police are not coming, but the natives have a plan to fight back.
After failing to start the logging trucks they have seized, the guardians burn them to make sure they are not used again.
"We asked them to leave, and they didn't," says Laercio. "We're burning the trucks now to show our response."