An American expat trades goods along the wildest reaches of the upper Amazon River in his old trawler boat. While stopping for supplies at a remote Peruvian village, a captivating woman asks for passage to the frontier town of Iquitos. He says he doesn't take passengers, and it will be several days before he returns to Iquitos-not mentioning that the police are looking for him there. She pleads for his help, saying she can no longer live in her village. He finally relents. But deadly trouble soon upends their journey, first pulling them together, then tearing them apart.