(Covers information from Anderson's universe)
In 2002, with support from her brother, Lisa sought and gained employment with Umbrella, assigned to the computer security division working out of The Hive. The purpose of this being to recover incriminating evidence of Umbrella's crimes, a task she was well suited to. When Alice, the Hive's security chief, requested a meeting, she revealed her ownplanning to move against Umbrella, and wanted Lisa's help to do it. She promised to help obtain data on the T-virus, in exchange for Lisa's promise to bring Umbrella down, a plan which Lisa readily agreed to.
Unbeknown to either of them, Alice's partner, Spence, had eavesdropped on their conversation, and was planning himself to steal the virus. He released the virus into the Hive's air conditioning system and made his escape. The Red Queen, in an attempt to stop a disastrous viral outbreak, sealed Lisa's office and filled it with halon gas, suffocating everyone within.
Hours later, as Umbrella's commando team came into the Hive to investigate the incident, Lisa's own brother, Matt went in with them to find her, or some of her gathered evidence. He was met by Lisa's corpse, reanimated by the t-Virus, who attacked him. Lisa was killed for the final time by Alice, who bashed her skull in with her own paperweight.