One (portrayed by Colin Salmon) is the captain of an Umbrella Special Ops team dispatched into the Hive to shut down The Red Queen AI in the first Resident Evil film. His real name is James Shade.
As the team approaches the Red Queen's central chamber, One and three of his squad are locked inside a corridor. The walls are all lined with laser emitters and beams begin passing through the corridor, cutting down each of the squad one by one while the team's computer expert Chad Kaplan is back outside the corridor trying to disable the defense systems. One manages to avoid several single laser beams, but then the lasers form a net pattern that fills the width of the corridor, giving One no space to dodge. Kaplan manages to disable the lasers and unlock the door, but just a moment too late. The laser grid passes through One and he collapses to the floor in a pile of meaty chunks.
Resident Evil: Retribution
One makes a reappearance in the fifth Resident Evil film. This One is actually a clone of the original who had DNA samples taken from him when he first joined Umbrella. The clone appears as one of many cloned commandoes in the Umbrella Prime facility in the Antarctic under the control of the Red Queen. He and several Umbrella grunts battle against Leon Kenedy and the other rebels employed by Albert Wesker to rescue Alice from Umbrella Prime. In the end, the clone One dies when he gets shot in the chest by Barry Burton.