When was the last time some experiment went right? But if the goal is creating hordes of zombies then all is ok. You aren't well at all but you have the chance to know what's going on. Shoot the zombies and reach kill score high enough to face the boos. The story is uncovered as you continue in the game. You can use simple map as well and it's good idea to walk through all the rooms where you can find a serum which with experience points improve your skills.