The cure is in the lab. With the help of your flashlight, search for the lost files of the cure. You must take the risk to survive. Once you enter, collect the file and the gold key in each room and unlock the door to get to the next section. If you hear their scary voices, be quick to get out of the room or push objects to obstruct zombies. You can also find some weapons on your way. Good luck!
Use W key or Up arrow and your mouse to move.