Walkthrough for Mother Superior Blues of Red Dead Redemption: Undead Nightmare.
1. Go to Las Hermanas marked with U on right of the Perdido to meet Mother Superior.
2. Go inside the town in front of you to save Nuns.
3. Go back to M mark outside the town.
4. Go find a zombie around the town and rope him down and bring him to Mother Superior.
5. Go to Sepulcro's graveyard marked with green skull and clear it.
6. Same as the other graveyards, burn the coffins and kill every zombie.