The story opens with an unnamed narrator on board the Nellie, a cruising yawl (boat) anchored in the Thames Estuary downstream from London and near Gravesend. He is with four friends, and dusk is falling as they wait for the turning of the tide. The narrator briefly describes the others, all of whom seem to be middle-aged men. One is called Charlie Marlow – the only one who "still followed the sea." Marlow makes a comment about London having been "one of the dark places on earth", and then begins a story of how he once took a job as captain of a river steamboat in Africa.