A Final Plan for Esteban

 is an unmarked quest in Fallout: New Vegas.

Quick walkthrough

 * Retrieve the corpse of the husband of NCR private Christina Morales. His body is located to the east of REPCONN Headquarters. Fiends have set up his body as a deathtrap, to lure in NCR troops. Take them out, grab the corpse, and carry it to the nearby NCR Troopers camped just northwest of where his corpse is found.

Detailed walkthrough
Heading south from Camp McCarran toward the map marker is one approach. Just north of the REPCONN Headquarters, the player will be approached by an NCR Trooper who offers some advice about retrieving the corpse. There are several options at this point.

After recovering the body and returning with the news to Pvt. Morales, Doctor Kemp at Camp McCarran will offer discounts on both medical supplies and services.

Bugs

 * The corpse of Ranger Morales will occasionally blink or get stuck in place.
 * Be sure that you talk to the NCR Troopers before you reach Ranger Morales' Corpse. Occasionally if you return the corpse before talking with the troopers, there is a chance they won't acknowledge you retrieving the corpse. Although, occasionally, leaving and returning to the corpse area (leaving the body there) can force one of the Troopers to appear to you and talk as if you hadn't attacked yet. At which point you can proceed normally.
 * Colonel Hsu doesn't always thank you for bringing the body back, after speaking to Pvt. Morales again.
 * Mines fail to appear around the corpse, while the Tripwire Shotgun and Beartraps are still in place.
 * Sometimes Pvt. Christina Morales disappears from the McCarran Concourse Hall after you have started it. If you go to the body, there are no NCR Trooper around to take it to.
 * Sometimes, if you mess about or leave the body at any point (or enter internal locations which require the game to go to a loading screen), it will disappear leaving no other option but to return to an earlier save point and return to the body's location to complete the quest.