As dusk begins to fall, the unnamed narrator of the story stands on the deck of his ship, currently anchored at the mouth of the Meinam River in the Gulf of Siam. The narrator is the Captain of the ship who leaves the deck to eat supper with his mates. The time is approximately eight o'clock.
At supper, the Captain remarks that he saw the masts of a ship anchored amongst some nearby islands. The Chief Mate explains that the ship to which the Captain is referring is probably another English one, waiting for the right moment to sail home with a favorable tide. The Second Mate elaborates: The ship is the Sephora, from Liverpool, and is bound home from Cardiff with a cargo of coal. (He learned this from the skipper of the tugboat who came aboard to fetch the Captain's letters.)
The Captain makes a magnanimous gesture by offering to take the anchor watch himself until one o'clock, after which time he will get the Second Mate to relieve him. Again alone on deck, the Captain meditatively smokes a cigar and again considers his own "strangeness" to the ship and its command. The rest of the crew sleeps soundly.
The Captain notices that the rope side ladder, hung over the side of the ship to accommodate the skipper of the tugboat, has not been brought in. As he begins to pull it, he feels a jerk at the other end and curious, looks over the rail into the sea. He sees a naked man floating in the water and holding the end of the ladder. The man introduces himself as Leggatt. He has been in the water since nine o'clock, which makes the Captain consider his strength and youth. Leggatt climbs up the ladder and the Captain rushes to his cabin to fetch him some clothes. The Captain learns that Leggatt was the chief mate of the Sephora and that he accidentally killed a fellow crewman. Although Leggatt unintentionally murdered the man, the Skipper stripped Leggatt of his title. The Captain tells Leggatt that they should retire to his cabin so as not to be discovered by the Chief Mate. The Captain hides Leggatt in his cabin, returns to the deck, summons the Chief Mate to take over the anchor watch, and returns to his cabin.
