Meanwhile, Claire is reunited with Sherry and discovers that William has implanted his daughter with an embryo to produce offspring. Leon, Ada, Claire, and Sherry advance through an abandoned factory connected to Umbrella's secret underground research facility. An attack by William leaves Ada heavily wounded, and Leon explores the laboratory to find something to treat her wounds. He is interrupted by a psychotic Annette, who explains to him that Ada's relationship with John was only a means of getting information about Umbrella: Ada is a spy sent to steal the G-virus for an unknown organization. Just as Annette is about to shoot Leon, the Tyrant appears, and she is forced to retreat. Ada returns to save Leon and battles the Tyrant – which falls into a pit of molten metal – seemingly at the cost of her own life. She confesses her love to Leon, who leaves behind her motionless body, however, Ada survives. Meanwhile, Annette tries to escape with another sample of the G-virus but is fatally wounded by her mutated husband. However, before she dies, she tells Claire how to create a vaccine that will stop the mutations caused by the embryo within Sherry. After preparing the cure, Leon and Claire reunite at an emergency escape train and inject Sherry with the vaccine, which saves her life. En route, Leon is assisted in terminating the now-mutated Super Tyrant by Ada who escapes with the G-virus in the pendant. William—now mutated into an agglomeration of flesh and teeth—follows Leon and Claire, but is destroyed when the train self-destructs. After escaping from the city with Sherry, Leon intends to take down Umbrella, while Claire continues to search for Chris. HUNK, one of the surviving special agents sent by Umbrella, completes his G-virus retrieval mission.