Eva in Peril

 is a stranger sidemission in Red Dead Redemption.

Story
Eva is a prostitute owned by a man named Mario in Casa Madrugada. When the player comes across this stranger mission, Mario is beating Eva for what would appear to be no plausible reason. Once the player intervenes, an offer of $200 to buy her freedom is presented.

Walkthrough
First off, make sure to not kill Mario. If you do, Eva will run away in fear. Give Mario the $200. After Mario accepts the payment, Eva will thank the player and make her escape to Las Hermanas, a Church just south east of the player's current position. The quest will then inform the player that you should check in on her after a few days. Once sufficient time has past (a day or two), a purple circle will appear around Las Hermanas. Upon arrival, continue to the end of the church and speak with the nun praying inside the church. She will confirm that Eva ran off with someone and they were headed to Sepulcro (a cemetery to the east).

Approach Mario and a cutscene will begin. Mario is digging Eva back out of a shallow grave but offers no explanation for this. He exclaims that he didn't kill her and that he only hit her, offering a possible explanation that he may have simply hit her too hard this time. Marston then asks whether he will get his money back before or after he kills Mario. A duel will ensue. Be warned: Mario is pretty handy with a pistol, you will need close to 100% on your gauge to defeat him. By checking the 'Strangers' under the stats tab, it will inform you that Mario killed Eva in a drunken rage.

After killing Mario, loot his body, you will recover your $200, and an added $5 along with Honor and Fame.

Trivia
If you walk away at the first encounter, you will fail the mission and have to restart it at a later time. If you kill Mario at the first encounter, the Mission will fail. Disarming Mario during the duel is not possible, and will end with the player's death.

There has been occasion where two Eva's spawn. They will get attacked by wolves, and when one of them dies, the mission fails, saying that Eva is angry that you attacked Mario.