Horsemen, Apocalypses is a main story mission in Red Dead Redemption 2 given by Sadie Adler, as part of Chapter 4.
It's the 55° mission in chronological order of the RDR2 story mode, played with protagonist Arthur Morgan.
Horsemen, Apocalypses - Mission Details:
The O'Driscolls send Kieran's mutilated body to the gang camp at Shady Belle, before launching a brutal attack.
Mission Objectives
Gold Medal Objectives (100%)
The following are the Mission Objectives required to obtain the Gold Medal in the mission "Horsemen, Apocalypses":
- Shoot the O’Driscoll’s in the boat before they disembark
- Complete using only sidearms
- Complete with at least 70% accuracy
- Get 15 headshots
- Complete the mission without taking any health items
Note: You must complete all Gold Medal requirements in one single playthrough of the mission.
Horsemen, Apocalypses: Mission Info
- Mission Number 55
- Story Chapter Chapter 4
- Mission Type Mandatory Mission
- Mission Giver
Sadie Adler - Protagonist (Playable)
Arthur Morgan - Location Shady Belle (Bayou Nwa, Lemoyne)
- Featuring
Kieran Duffy 
O'Driscoll Boys Gang