For this Stranger to appear on the world map in Red Dead Redemption, two conditions must be met: complete the Abraham Reyes mission «The Gates of El Presidio» and ensure the time is between 18:00 and 7:00. Head to the town of Blackwater to the marker on the map to start this mission.
Talk to Clara LaGuerta in the Blackwater church. The girl will mention that she was seduced by her employer Harold Thornton and is now pregnant. Thornton fired her as soon as it became clear she was pregnant, and since then, he has become an alcoholic. Your task is to find Harold to get money from him for the girl's support with the newborn. Harold Thornton is in the Blackwater saloon. Get there and talk to the character. He will, of course, deny everything and seem confused, forgetting that he ever hired or knew Clara. Additionally, he will challenge the protagonist to a duel. Using the unique "Dead Eye" ability, kill the man and collect the money from his corpse.
Return to Clara in the church to give her the money you obtained. She will then run away, and the mission will temporarily become inactive until a short period of in-game time passes (about three days). After a few days, head to the chapel cemetery to find Harold's wife, Elizabeth Thornton, crying at his grave. She will mention that Clara attended the funeral. You will realize that you may have made a mistake by killing the man. Rewards: