When you can't breathe, you can't scream!
A documentary film crew headed by anthropologist Steve Cale (Eric Stoltz) and director Terri Flores (Jennifer Lopez) travel down the Amazon River in search of a long-lost indigenous tribe. On their journey they save a man, Paul Sarone (Jon Voight), from a sinking boat. He offers to help in their search for the tribe, but he is actually a snake-hunter looking for the legendary green anaconda. When an accident leaves Cale unconcious, Sarone takes charge of the boat, steering the rest of the crew into grave danger.