Intro. Ada Wong infiltrates a secret Umbrella Corporation laboratory beneath Raccoon City. There she finds a tied-up test subject on whom brutal experiments were carried out. The person (user) was infected with a new, yet unknown virus called "Arachne". This virus: strengthens reflexes and danger instinct temporarily increases strength and regeneration forms nerve-like structures in the body that appear like a dark "net" under the skin In extreme cases, it can take over the personality of the host However, the test subject shows an unusually high level of compatibility, which means that the mutation does not go as planned. As the lab descends into chaos and self-destruction is activated, Ada frees the person and escapes with him - knowing that she has introduced an unpredictable new variable into play.