Mara O’Hanaran was a rising star in the NCR Rangers until a botched recon mission led to her capture by the Fiends. The trauma she endured at the hands of Cook-Cook shattered her faith in the Republic's ability to protect its own. She’s been by your side since you saved her from certain death at the hands of raiders in the wastes of the Mojave. You could always tell Mara was hurting inside, even if she never talked about it.

You and Mara are traveling down the I-44 one day, heading back toward New Vegas when Mara stops you, and asks you for a favor - She’s been thinking about the past a lot lately, and thinks it’s finally time to resolve it only way she can think of - by killing Cook-Cook and plenty of fiends alongside him. It’s up to you to either help her out, or figure out another way to help Mara come to peace with herself.