There will be a man on a boat with a zombie in this chapter. Save the man and Amy will get a call. You will then look at the bottom of the boat. Depending on your current score, you will get a powerful item. Alternately, do the step described previously after selecting either a shotgun or grenade when starting the game. Where the zombies jump down, kill them then wait for the last pair. When they land, there is a door behind the one on the left. Shoot the door and the woman will say "Good luck" and hand you either a shotgun or grenade launcher.