At the beginning of the scenario you'll start near a gun pick it up.
Before the zombies break in the front door go in behind the bar and pick
up the key to the door that's locked. Unlock it go in and zombies will
break thru a window. don't worry about them let your partners take care
of them. (if u want to get in front of the door and hold it). At the end
of the scenario when your in the street full of zombies behind a
barricade to get the detonator go diagonally right and then go
diagonally right. Then combine them and go to the corpse in the middle
of the road (where the case is and use it and that's the end of the
scenario.