Red Dead Redemption II Legendary Gunslingers Black Belle
Approach her house and she'll ask you if you intentionally brought those bounty hunters do her door. Help her fend off the onslaught of enemies and make sure she stays alive.
There are multiple switches along her house which will trigger explosions. Belle will generally tell you when it's good to hit them to be most effective. Also make sure to prioritize the mounted gun when it shows up, as well as take out any new enemies headed to use it.