Isn’t this Leon trying to escape from the campus? But the door was locked and he asked for the employee key. Then Leon and others went to look for it. Then they were attacked by zombies, but they still managed to open the security door and go looking for it. The key to the door. That's right, you can find the key at the end. The second to last room is the room where you will enter the room with the key next. Well, if you don't understand, after you get the key, go back and open the door to enter. There is a table in a room. The blue sign of the double-headed snake is inside the table. Get close to the table and press the space bar to pull out the drawer (you have to be facing the drawer). After you pull the drawer open, you will find the blue sign. Well, if you really can’t find the blue card, you can look for graphic guides or video guides. Experts who have passed the level will tell you the locations of even 10 pistol bullets. Note that this is not an exaggeration. However, if you read too many guides, the surprise of the game will be gone. It is not recommended to read too much.