Jill Valentine is a character in the Resident Evil series. Valentine is an American counterterrorism officer who works with her partner, Chris Redfield, to fight the Umbrella Corporation, a pharmaceutical company whose bioterrorism creates zombies.
In the Spring and early Summer of 1998, Raccoon City was haunted by the deaths of a number of hikers and suburban families. Their deaths implied both vicious dog attacks and group cannibalism. With the Raccoon City Police Department at a loss, S.T.A.R.S. was given orders to head into the Arklay Mountains in search of a suspected hideout. Bravo Team was sent out on the night of July 23, and contact was subsequently lost. The following day, the Alpha Team was sent out to investigate their disappearance and continue their investigation. Finding the helicopter derelict and its RPD pilot, Kevin Dooley, dead and mutilated, Alpha Team was confronted by a pack of dogs who then killed Joseph Frost. Jill; Chris; Barry and Wesker fled into a nearby mansion, while Brad, in shock, fled to the helicopter and abandoned the team.
Within the mansion itself, the four team members split up and explored the mansion on their own. Over the course of the night they pieced together independently that the mansion was the facade to a bio-weapons research laboratory under the control of Umbrella U.S.A., S.T.A.R.S.' biggest donor. Jill began to suspect Barry was working against the team owing to a series of suspicious actions, but later discovered Captain Wesker had manipulated Barry with threats to have his family. Wesker was in fact on a mission from Umbrella to retrieve bio-weapons research, then destroy the laboratory and kill the S.T.A.R.S. team to silence witnesses. The dog attacks and cannibal murders were found to have been the result of the t-Virus, a bioweapon which had leaked out into the surrounding area. With Wesker faking his death when activating a renegade bioweapon designated "Tyrant", Jill; Chris; Barry and Bravo Team's Rebecca Chambers escaped the lab before its destruction on Brad's helicopter.