Eventually, Rebecca and Billy catch up with the leech-controlling man, who happens to be Marcus' final experiment, Queen Leech. Ten years earlier, Marcus was assassinated on the orders of Umbrella's other co-founder, Oswell E. Spencer, who sought his research. After his corpse was dumped, Queen Leech entered his body and reanimated it, gaining his memories and the ability to shapeshift, whereupon it believed itself to be Marcus and orchestrated the T-virus outbreak in the facility and on the train as a means of revenge against Umbrella. After temporarily defeating it, Billy and Rebecca attempt to escape to the surface via a lift, just as William Birkin trips the facility's self-destruct mechanism. Pursued by Queen Leech, the pair eventually kill it and escape before the facility is destroyed. Following their escape, Rebecca notices the mansion that Marini mentioned and prepares to head for it. Before she does, she assures Billy that her police report will list him as another casualty of the incident. Thanking her for his freedom, Billy departs as Rebecca heads towards the mansion to seek out the whereabouts of her fellow Bravo Team members (seen in "Resident Evil").