This Unnamed Marine fought during the Human-Covenant war and served in Ghost's platoon.
Sometime during the war, she fought under the command of Sergeant "Ghost." She was close to him, and greatly admired his leadership skills. However, she was deeply saddened by Ghost's demeanor—he was cold, did not display emotion, and even appeared to lack humanity.
After heavy combat on an unspecified planet, Ghost's entire Marine platoon was wiped out by the Covenant attack force. The unnamed Marine was mortally wounded. Knowing she was close to death, she asked Ghost to promise her to just act like a human being for once. Soon after, she became the last fatality in Ghost's squad. Ghost was greatly saddened by her death.
Her last words to Ghost appear to have motivated his actions three years later, during the Battle of Algolis. Ghost was tasked with destroying navigation data and a Prototype Powered Exoskeleton as per the Cole Protocol. He disobeyed direct orders, using the armor to hold Covenant forces back while his men evacuated the area. He used the armor's self-destruct function to kill himself and the surrounding Covenant attackers. His last words and thoughts were of the promise he made to the Unnamed Marine.
- It is likely that the Marine suffered from a shrapnel injury due to the fact that no plasma scorching is visible on her armor so perhaps a fragmentation grenade or other debris had injured her.