Marlow's Fresh-Water Sailing Story

Marlow is an explorer. "He is the only man of us who still 'followed the sea," says the unknown narrator who seems to be a crew member on the Nellie. The sea is greatly revered by the sailors who share the "bond of the sea" as well as the bond of the Nellie. It is a lazy day on the Thames River as the Nellie lazily lulls closer and closer to the ocean when Marlow begins his tales of his time as a "fresh-water sailor" on a long, snake-like river in Africa. As a child, Marlow constantly studied maps. He "had a hankering" after Africa as a young boy, and as he grew old, this fascinating, mysterious place became a "place of darkness." When he scores a job on a French steam boat that moves along the coast of Africa, what he sees shocks him. He becomes "acquainted with a flabby, pretending, weak-eyed devil of a rapacious and pitiless folly." He witnesses a cliff being repeatedly blasted for no apparent reason. Marlow's interpretations of what he sees are never stated, but rather implied. When he sees the native people being enslaved and crawling off to die, turning into "black shadows of disease and starvation," he clearly thinks the methods of buisness in this part of Africa to be more destructive than productive. There seems to be a conspiracy working with the buisness Marlow is involved in but he cannot figure it out. It has something to do with Mr. Kurtz, who we learn about through the dressed-to-impress Chief Accountant. The flabby, weak-eyed devil is present in all aspects of this situation in which Marlow finds himself.
What do you think of this conspiracy? and Mr. Kurtz?