A veteran member of the Gunners, Sergeant Lanier was the commander of a Gunner moderate detachment to explore the western areas of the Commonwealth, when they came upon the Nuka-World transit center. After putting a bullet into some guy who was obviously acting as a lure, Lanier decided against trying to use the monorail and hoofed it over the mountains. Rough terrain eventually caused them to lose communications with Gunner HQ, but Lanier pressed on, accustomed to doing ops without a lifeline to HQ. Confident that a follow-up team would be sent in case things go awry, she continued on, to verify the presence of a trading post out west. Upon arrival in the Nuka-World area, the group set up camp at the Bradberton overpass.
Although she was unfamiliar with the concept of amusement parks, she knew that Nuka-World had value. Every park was almost like a ready-made fort, ready for occupation. All that she had to figure out was how to push out the raider tribes and get to work. Further recon confirmed that the operation would be hazardous without a larger force or power armor support, as Nuka-Town USA was too well fortified and manned for them to try to attack, while the Kiddie Kingdom was covered in radioactive mist. Eventually, as recon reports accumulated, Lanier decided to hit the Nuka-Cola bottling plant first. She made her first mistake there, leading the push herself, in what was supposed to be a simple tag & bag operation. She did not foresee the nukalurks. Although the Gunners put up a valiant defense, setting up traps, kill zones, and bringing plenty of firepower to take down the nukalurks, their seemingly inexhaustible numbers eventually overwhelmed the Gunners through sheer attrition. Lanier led the remnants in a desperate last stand by the Quantum bottler, but eventually succumbed to her wounds.