Half-Life 2: Zombie Master Office Map (Alpha 2)

You and your co-workers have made it to the roof to be rescued by a helicopter, but it simply dropped ammo crates and flew off. Now you have to go back into that nightmare, and call a new helicopter.
Survivor Objectives 1), Take the roof access elevator down into the basement. 2), Force your way to the offices. 3), Find the Boss' Room Key by walking over the corpses in the offices. 4), Use the boss' phone to call for help. 5), Go back to the