Despite his youth, Mouse is an excellent programmer and claims credit for designing some of the training programs used by the Neb crew, such as the Agent training program featuring a woman in red. While something of a hedonist, he also has a rather philosophical outlook of the world. During mealtime aboard the Neb, he discusses with Neo the possibility that the Machines botched humans' sensory perception when designing the Matrix, i.e. the taste of simulated food.
When the Neb crew jack into the Matrix to take Neo to see the Oracle, Mouse remains on guard at the Lafayette Hotel. As the others make their way back, the Matrix simulation alters and the windows all turn to brick, trapping everyone inside. Mouse is alone in the exit room when a SWAT team bursts in and he is gunned down.