Once locked within the country Marlow finds his surroundings extremely harsh: The Congo is described as a place of intense mystery whose stifling heat, whispering sounds, and strange shifts of light and darkness place the foreigner in a kind of trance which produces fundamental changes in the brain, causing acts that range from the merely bizarre to the most extreme and irrational violence. (Telegan 98) In the above mentioned quote Diane Telegan sums up the theme of light and darkness and even goes on farther to discuss the effects of it to a human. She suggests that it is the setting of the Congo that causes Kurtz to go insane. The setting causes many of the characters to go insane, " The sun was too much for him, or the country perhaps- (Conrad 80). Marlow says this as he views the body left hanging on the limb of a tree after the native took his own life. Marlow assumes that the native killed himself because he could not deal with life in as harsh as a setting as the Congo is. This is at the beginning of the novel before Marlow has begun on his journey within his heart. Perhaps if his journey had already begun, Marlow would have assumed that it was the darkness that he could not live with. Shortly after this scene Marlow begins his journey to the inner station. Once on the journey into the Congo it is very important to notice the transformation of the jungle itself as Marlow travels closer to Kurtz. When Marlow first enters the Congo it is not that dense with forest. The sun flows heavily through the trees causing great discomfort. Once Marlow is aboard the ship and on his passage down the river the forest becomes more and more impenetrable. The river is dark brown and just barely flowing, the forest becomes so thick right before they reach the inner station that the men aboard the steamer could not even see the savages that would soon ambush their boat. Once at the inner station the setting alters to that of infernal worship.