Rebecca Chambers was a rookie officer of S.T.A.R.S. assigned to Bravo Team under the position of RS (Rear Security). She was in charge of medical and possessed extensive knowledge related to chemistry. Although she was an action type and little upset her, she held no real experience in actual combat. When trying to act boldly she often hesitated, and when overwhelmed by a situation, she couldn't help but expose her lack of experience. She gained her first actual combat experience during the investigation into the bizarre murders in Raccoon Forest.
History
By the time she was 18 years old, Chambers had excelled in education and graduated college early with excellent grades, although without obtaining a degree. She is believed to have been a veritable child genius. In June 1998, she joined "S.T.A.R.S." (Special Tactics and Rescue Service), the unique Special Forces unit of the Raccoon City police department. She was recruited specifically for her knowledge in chemistry despite her lack of field experience and due to her young age and inexperience, fellow officer Richard Aiken was charged with looking after her.
When at work, she wore a beret and shoulder pads similar to Jill Valentine, but sometimes wore lighter clothing. To show that she was a medical professional, she was equipped with a red and white nurse wristwatch equipped with a pulse meter for monitoring injured individuals.
Ecliptic Express Incident (Jul. 23, 1998)
On July 23, 1998, Chambers was dispatched with Bravo Team to investigate a series of bizarre murders in the Arklay Mountains. The team's helicopter made a forced landing in the forest due to engine difficulties. While investigating the area, they discovered a wrecked military transport which had been carrying former Marine Billy Coen, who had been sentenced to execution for multiple murders. Investigating further, Chambers found and boarded a train which had stalled in the forest. Upon entry, she discovered several Zombie creatures. Billy Coen was also on the train, and despite their mistrust of one another, they were forced to cooperate to survive against the creatures which had overtaken it.
The train took Chambers and Coen to an abandoned executive training school formerly operated by the Umbrella Corporation and run by founding member James Marcus. Further investigation led the pair to Marcus' private lab and to an Umbrella Sewerage disposal plant. As they aided each other, they began to form an unshakeable trust, and Chambers began to see Coen's murder charge as a false accusation.
At one point, the two were attacked and separated and Chambers encountered Bravo Team Captain Enrico Marini. He requested that she come with him to a nearby mansion, but Chambers declined in favor of finding Coen. A reluctant Marini eventually agreed. After finding Coen again, they were confronted by a revived Marcus, who was in reality a "Queen Leech" created by him ten years ago which had managed to clone his body and memories shortly after he was killed. After destroying the Queen Leech, Chambers swore to fake Coen's death and the pair parted ways, with Chambers heading toward a mansion, known as the "Spencer Mansion", where she expected to regroup with the other S.T.A.R.S. members.
Mansion Incident (Jul. 24, 1998)
Chambers took refuge in a dormitory in the guardhouse of the Spencer Mansion and fell asleep due to her exhaustion from the night before. During this, she apparently experienced a nightmare involving a giant snake. She was discovered by fellow S.T.A.R.S. Bravo Team officer Richard Aiken. Together, the two searched for Captain Marini and made their way into the mansion where they believed their teammates would be, but they were instead pulled further into disaster. During this time, they were attacked by a giant mutant snake dubbed "Yawn" and Aiken was bitten and poisoned in the process of protecting Chambers.
Later, Chambers was found by S.T.A.R.S. Alpha Team member Chris Redfield, who had brought serum which helped cure Aiken. This gave Chambers new hope for their survival, and she used her abilities as a medical officer to their fullest, supporting Redfield as they worked together in investigating the mansion and searched for an escape route. Eventually, they were rescued alongside Jill Valentine and Barry Burton by Alpha Team helicopter pilot Brad Vickers.
Upon her return to work after brief hospitalization, Chambers wrote her report on the incident in which she detailed Billy Coen's "death". What happened to her after that is unknown, but she is believed to have left Raccoon City before the biohazard outbreak in September 1998.