Sadie Adler's mission is one of the additional missions in RDR 2. the location is Beaver Hollow Camp. As a reward, Arthur will receive a higher level of honor. The mission will be available after completing the "goodbye, old friend" quest.
Sadie Adler's widow wants to avenge her husband's death and the destruction of the ranch. To do this, she asks Arthur to go with her. He can also do it on his own, for this he will need to get to the Hanging Dog ranch.
After Morgan gets close to the ranch, there will be a short cut scene. Immediately after its completion, a shootout will begin. Arthur will need to use the skill "Sharp eye" and cover to eliminate all targets. The sniper will aim from the upper window of the barn, you need to eliminate it with an accurate shot to the head, this, by the way, will be the first step on the way to getting a gold medal.
Once the courtyard is cleared of enemies, you will need to check the buildings. Sadie will go to look at the one on the right, while Morgan will have to explore the barn. Here you should be careful, as the remaining enemies can hide in the shelter. If the shed is released without damage, this will be the second step towards getting a gold medal at the end of the mission.
Next, Arthur will need to find Sadie. He finds her in the house, where she kills the man she originally planned to kill.
To get a gold medal. you will need to complete this mission in 5 minutes and 30 seconds.