About fifty miles from the Inner Station, Marlow comes across an abandoned reed hut near the bank of the river. Written on a flat board sitting on top of a stack of firewood is the message: "Wood for you. Hurry up. Approach cautiously." When Marlow arrives at the Inner Station, he is greeted by an enthusiastic individual, who resembles a harlequin. The Harlequin mentions that he wrote the message on the wooden board warning Marlow and his crew to approach cautiously. The Harlequin tells Marlow that it is common for canoes to get upset near the location of the reed hut on the river, and mentions that he struggled to keep the Natives off him throughout his journey. When Marlow asks the Russian why the Natives attacked their steamboat, the Russian responds by saying that the Natives do not want Kurtz to go. The Harlequin then enigmatically says that Kurtz has enlarged his mind.
Although Marlow doesn't realize it at the time, this message is left for Marlow by the Russian. Marlow knows something is wrong, but is not
sure what. They look into the jungle, but find no clues. In the hut, with a plank on two posts serving as a table and rubbish in a dark corner, he finds a coverless book about seamanship with notes written in a language Marlow does not understand. Finding the book and looking at the notes are an “extravagant mystery” for Marlow. His quest to save Marlow becomes more urgent.
What do you mean by quest to cave Marlow?