"It's a bug hunt." - Hicks, regarding the mission
He appears in Aliens. He is a member of the Colonial Marine Unit, who has to find out, what happened in the moon LV-426 and is deployed there aboard the USS Sulaco in 2179. He is the third in rank and he is a natural born soldier because of his capacity to think straight and be calm, even in stressful, dangerous situations.
When the unit's commanding officer, Lieutenant Gorman, was incapacitated during the first batlle with the Xenomorphs and Sergeant Apone taken prisoner to be used for the breeding of another Xenomorph, he took command of the remaining unit with the support of Ripley, whom in his wisdom he shares command with. He develops feelings for Ripley and respects her ability to think straight and lead the soldiers. He also teaches Ripley to use weapons, which proves decisive in saving Newt.
He survives the fight against the Alien Queen together with Bishop Newt and Ripley, but is badly wounded because of alien acid that was thrown on him by a dying alien, for which he later has to receive a sedative by Bishop.