An AMS agent at age 27, Stick's parents were scientists and members of GOD, who were involved in the government's top secret UDS (Undead Soldier) project, designed to turn the dead into military weapons. His father, Gil Breitling, is credited with the creation of the Gil Cell, which had a large impact on the development of the UDS project. Stick's mother passed away when he was six years old, and his father disappeared shortly after, who has not been seen since.
Partnered with fellow AMS agents Linda Rotta and Rikiya Busujima, he is tasked with eliminating the zombie threat and track down the man responsible for spreading the virus, ZED. Stick understands the Japanese language, which allows him to communicate with Busujima, who speaks Japanese but understands English.
Following the steps left behind by ZED in his game of cat and mouse, the agents fight their way through Woodside City as they hunt him down. Surviving the explosion of the city's chemical plant, he and the others stop a runaway train carrying the virus from crashing. ZED appears before them and reveals his goal to kill all humans by releasing a powerful UDS he holds in his body that he calls the "God of Destruction". The room is then filled with knockout gas, and ZED, impervious to its effects, singles out Stick as the one who must suffer the most before he and the others lose consciousness.
The agents find themselves on Mt. Sacrifice in front of a mansion and head inside. ZED later reappears, explaining the purpose of the UDS project and reveals that his parents were a part of it. However, at some point they were killed and used as experiments by a scientist named Gil Breitling; Stick's father. ZED has since vowed revenge, expressing his desire to kill Breitling as well as all other humans before sending the agents underground into his base of operations where he finally confronts them. Defeated, the agents cautiously approach ZED's body, only for the God of Destruction to be released. After a grueling final battle, they put the ultimate UDS to rest.
The agents are then transported to a desert, where they all reflect on ZED's words and the truth behind the experiments. Stick begins to express his shame toward his father, but is stopped by Busujima, reminding him it's in the past. A helicopter comes by to pick them up, piloted by fellow agent Marco Cloud. Busujima remarks that they have a lot left to do, which Stick acknowledges with other thoughts on his mind.
- Statues of Stick Breitling and Rikiya Busujima were created in order to promote the game in Japan.
- Stick's third outfit, exclusive to the Dreamcast original mode, has him wearing red robotic armor.
- Throughout the game, he is attentive toward Linda's well-being, leading players to question if there are any romantic connections between the two.