"Jeremy travels to the heart of Africa and journeys up one of the few rivers left on Earth that truly tests the will of even the most seasoned fisherman. This is the Congo, a river shrouded in mystery, steeped in legends and soaked in violence. There is one spirit in particular, called "Mami Wata", that is said to lure fishermen from their boats and send them plunging to the bottom of the river where they are imprisoned for all eternity. Far-fetched? Maybe not. Jeremy discovers that the truth is every bit as frightening as the myth."
Jeremy Wade travels to the Congo once again, the only river to ever defeat him. He had once travelled there, only to catch nothing. Now he's back, investigating reports of fishermen being dragged to their death by a malevolent river spirit.
Wade suspects the Suni or Vundu catfish and the Kamba catfish, which are known to grow to large sizes. But he begins to wonder if there are any monstrous sized fish out there in these waters.
While staying with local villagers, he faces their superstitious beliefs because they blame his arrival for the disappearance of the chief's brother. Even mosquitoes are deadly here. In the past, Jeremy nearly lost his life to malaria.
After using traditional Congolese fishing methods, hearing of how one fisherman died, and finally facing a catfish, Jeremy begins to wonder if the real danger isn't the fish itself.