Gibson was a squad leader who participated in Operation Deliverance.
Having survived the initial landings, Gibson was amongst the Rangers who rallied at the bus depot under the command of Captain Winters where they launched a succesful, albeit risky offensive to capture the bus depot from Chimeran forces.
During the battle, Gibson was ordered by Captain Winters to attack the Sentry Guns in the building furthest from him. However, unaware of the dangers of said Chimeran defense entrenchment, he and his squad were quickly wiped out, and fellow Ranger Payton was ordered to try and attack the same Sentry turret again with the same results. Eventually, Sergeant Hale was able to eliminate said Sentry unit by flanking them