- “No spook is gonna leave my kids in the dark, Benti would haunt me if I did, and she'd be a *real* annoying ghost.”— Lopez
Sergeant Lopez was stationed on UNSC Red Horse during the ship's mission in Installation 04's debris field in the Soell system. During the mission, a life pod of unknown origin was found by the ship. After wrenching the at the hatch, a man only referred to as "John Doe" was found. Apparently, the man was found mumbling some words about the not yet known Flood and also about a UNSC prisoner ship known as the Mona Lisa.
Under orders from Commander Tobias Foucault of Red Horse, Lopez led a small squad aboard Mona Lisa, where she was ambushed by an unknown hostile. After the ambush, Lopez and her men split into two teams. While scouting the medical bay, Lopez found an ONI Major named John Smith locked inside a safe room. As they interrogated Smith about the experiments with the prisoners and the Flood, Smith broke free and killed two members of Lopez's team with a concealed knife, leaving her with MacCraw, a fellow Marine.
After the incident, Lopez and MacCraw headed to the bridge of the Mona Lisa in order to enact the Cole Protocol. There they learned that not only had Smith stolen their only Pelican, but a Shiva nuclear missile was being prepared for launch against Mona Lisa. Foucault then told Lopez that two escape pods were left on the lower deck, omitting the fact that the pods were designed for single occupants.
As Lopez and MacCraw defended the pods, Corpsman Ngoc Benti arrived with Clarence, a prisoner named Patrick Rimmer, and his Sangheili companion, "Henry." Clarence, under strict orders from ONI to not let anything but the Marines leave the ship, executed Rimmer. Angered, Henry began to strike at Clarence with his cricket bat until Benti, who had already been heavily wounded on the way and showing signs of infection, sacrificed her life by pushing both herself and Clarence into the oncoming Flood horde. MacCraw then escaped in one of the escape pods, leaving both Henry and Lopez to fend for themselves.
As the timer for the Shiva launch reached thirty seconds, Lopez and Henry fled into the airlock only to find that the pod couldn't fit them both. Lopez was last seen fighting with Henry for the escape pod with only ten seconds to spare. Lopez probably died in the fight for the pod as she was already wounded, had no ammunition left in her assault rifle, Henry was armed with a cricket bat and, as a Sangheili, is physically far stronger than a human. Even if she survived the fight, she would have likely been killed by the blast of the Shiva nuke.
- Lopez is apparently religious, as she constantly remembers the smell of pews at her mother's church and commonly refers to her subordinates as her "rosary beads."
- According to her name, she is most likely of Chinese and Hispanic ancestry.
- Her squad nicknamed her Mama Lopez.
- Halo: Evolutions - Essential Tales of the Halo Universe
- The Mona Lisa (First appearance)