You see a video of Quill talking to you. She wants to take her time killing you. Lovely.
Shoot tons of mutants from within the windows. Wave after wave of them come. Eventually blast way out of your area. Go around through the little buildings.
go into little building and start shooting soldiers. through catacombs, more zombies. Have night vision on. up into main area and shooting soldiers. get to room with Quill in it. She's in top part of church on a balcony in front of giant window. She's not very good, and snipers on sides with grenades. Shoot them down with heavy machine gun. Use sniper rifle and rail gun on her - 3 medpacks next to the altar. Rectangle with triangle on one end, She's in the triangle. YOu want to be in bottom left area. A little down from tip of triangle is altar and seats. Bottom left room is ammo. Sides - runways - bottom left and bottom right have windows. Snipers come from opposite window. eventually you kill her. You get precision sniper rifle. Helps you aim with x/y notes.
walk into one door of a building - loading ... room full soldiers, kill all. loose piles boards at end of room - shoot - jump down catacombs, lots of zombie people. Wander through for a while. Get up into cathedral.
in though little door. Quill taunts you from a balcony with giant window behind her. snipers throwing grenades down at you, zombies with pistols on ground. stay in starting room, sniper rifle/rail gun, know how many keys to machine gun. Step out, shoot at quill and machine-gun snipers, step in and reload. pretty big health bar. Finally she flies backwards thro window, yu get her gun. Fsat sniper rifle auto 40 shot clip.