Left 4 Dead/No Mercy

No Mercy takes place in an urban setting, starting right where the introductory movie leaves off. The ultimate goal is to get to the roof of Mercy Hospital for a helicopter rescue; survivors must navigate through an apartment block, a subway system, and an abandoned warehouse, then cross the rest of the city in a sewer system to get to Mercy Hospital. The final two chapters has the survivors fighting their way up to the roof of the hospital and making a last stand until help arrives. Curing the Infection...One Bullet at a Time