Beck (THE ROCK) is an L.A. bounty hunter who's big and resourceful enough to get whomever or whatever his boss, Billy, wants. What Beck desires, however, is to get out of the business and open his own restaurant. His boss agrees to let him do that, but only if he completes one last job.
That's to travel to the Amazon and retrieve his boss's errant son, Travis (SEANN WILLIAM SCOTT), who's searching for treasure but has gotten into enough trouble that his angry dad has had to bail him out. Flown into the jungle by Declan (EWEN BREMNER), Beck imagines he'll find and retrieve Travis with little fuss.
After making a deal with businessman Hatcher (CHRISTOPHER WALKEN) who uses the locals as slave labor to mine gold, Beck finds Travis and his bartender friend, Mariana (ROSARIO DAWSON). Hatcher has a change of heart, however, and won't let Beck remove Travis. That results in an altercation that has Hatcher and his right-hand man, Harvey (JON GRIES), wanting all of them dead.
Following various perilous encounters with them, native rebels and some amorous monkeys, Beck tries to fulfill his mission, all while Travis and Marianna try to retrieve a legendary gold piece that both believe will help them in their respective quests.