Chad Kaplan (portrayed by Martin Crewes) is the computer expert and second-in-command of One's special forces unit, as well as the tetartagonist in Resident Evil. He is also the most inexperienced member of the team, yet One trusted him enough to tell him his real name.
During the film, Kaplan is tasked with disabling all of the Red Queen's defence systems as his team venture deeper into the Hive. When One, Olga, Vance and Warner enter the corridor to the Queen's chamber with the EM surge device, they are suddenly locked inside. Outside the corridor, Kaplan works frantically to shut down the lasers sweeping the corridor, but by the time he deactivates them, all his comrades have been carved to pieces. This deals a serious blow to Kaplan's confidence and his fear and guilt are evident throughout the rest of the film.
After shutting down the Red Queen, Kaplan, Alice and Spence regroup with Rain, J.D. and Matt. They are then attacked by zombies that have been released after the Queen's shutdown unlocked all the doors in the facility. Kaplan tries to open a door that is still locked but in his panic he forgets it. J.D. manages to input the code, only to find another group of zombies behind the door, which pull J.D. inside while Kaplan and the others escape.
Later, when the remaining survivors are trying to escape the zombies in the utility tunnels, they crawl across a pipe hanging from the ceiling. The pipe gives way under their weight but the group manage to scrabble away from the zombie masses. Kaplan is unfortunately bitten and infected with the T-virus as well as cut off from Alice and the others, who make it into an air duct leading back to the main lab area. Kaplan demands that they leave him behind and he prepares to kill himself using his last bullet, but changes his mind at the last moment and kills an approaching zombie. Mustering all his courage, Kaplan manages to escape the zombies and make it back to the lab area. When he arrives, he finds Alice, Rain and Matt locked inside a flooded room and the Red Queen is refusing to open the door. In response, he activates the Queen's killswitch and shuts her down permanently, which unlocks the lab door and frees the others.
The survivors make it to the escape train (where unkowablest to Kaplan, Spencer was revealed to have driven the plot, which led to him getting bitten after betraying the others before being killed) and Kaplan is administered the antivirus. Unfortunately, he still dies when the mutated Licker tears into the train and grabs him in its mouth, pulling him out of sight.