(The Tinhangse Publishing mythos)
Rebecca was a member of S.T.A.R.S., a police special forces unit in Raccoon City.
As a young girl, Rebecca went with her family camping in the Arc Lei Mountains. During this trip, her mother and younger sister were infected with a virus and transformed into zombies. Her father killed both of them and shot himself.
As a young adult, Rebecca successfully joined the S.T.A.R.S. Bravo Team. Still a rookie officer during S.T.A.R.S.' investigation of the mountains, she was ordered to avoid any conflict while exploring a train with Joe and John. Finding herself in a laboratory, she realised the train was being used by Umbrella for research. Soon after, Joe and John got caught up in a gun fight, and a group of uninfected guinea pigs escaped their cells. In the confusion, one of the men, Tom, punched her straight in the stomach to get her out of the way of the door. Another detainee, Billy, stayed behind to check on Rebecca.
When the men were ambushed by Umbrella, Tom destroyed much of the train carriage in a suicide bombing. With Billy injured by the blast, Rebecca used her medic skills to treat him. Immediately after waking up, Billy shot a zombie about to attack Rebecca from behind. Agreeing to explore the train together, they were soon after confronted by mutant rats in the train's bar, and following that a giant scorpion. After Billy was thrown around by the creature, Rebecca fired at some alcoholic bottles to cover the scorpion; Billy symbiotically knew to light the alcohol with a candle. Unable to kill it with the fire, the two led the scorpion to the end of the carriage, where they set off a gas tank to explode, decoupling the carriage and leaving the creature behind.
The explosion caused Rebecca to fall off the edge of the train, but Billy saved her from dropping to the tracks. She then handcuffed the man, but her inexperience led her to damage his arm and she had to nurse it in one of the cabins. Billy began experiencing a violent headache and physically attacked Rebecca; luckily, she was able to bring him back from his PTSD delusions. With more zombies left on the train, they realised the cabin was no longer safe and tried to escape via a hatch. Billy was unable to follow her, and tried to commit suicide while zombies bit him. Rebecca meanwhile ran into her zombified teammate, Joe, just before he was torn to shreds by a Hunter B.O.W.