It is directly behind the teacher's desk, and you will need the blueprint from Nate's locker to enter the secret room.
Use the stink bomb to get rid of the teacher. (You make one in the Science Room by mixing yellow and blue chemicals and heating them.)
you put the stinkbomb on the floor of the detention room and the teacher will leave then you click on the filing cabinet
You use it when you get put in detention for chewing gum so you can get into the filing cabinet.
The entrance to the secret room under the detention room is in the filing cabinet.
You are only in detention to get into the filing cabinet, which has a secret passage behind it. Before chewing gum to get detention, there are two things you need : a stink bomb and the blueprint from Nate's locker. (see related question)
in the detention room.
The entrance to the hidden room is in the second drawer of the filing cabinet. You need the blueprint from Nate's locker to access the room.
It is in the secret store room behind the filing cabinet in the detention room on Big Nate Island. You need the blue prints from Nate's locker in order to access the secret room.
you can not. you have to go in it.
Among the tons of junk crammed into the locker is the blueprint to the school. It shows the secret room behind the filing cabinet in the detention room. (see related question)
As you go into the floor behind the filing cabinet in the detention room, the light switch is right at the bottom of the ladder, on the floor.
Once you use the gum to get detention, and use the stink bomb you made in the science lab, you should be able to get into the cabinet. You must get the blueprint from Nate's locker before you can go down to the secret room.
The filing cabinet is on top of the entrance to the secret room where the missing bell clapper is hanging. Get the blueprint from Nate's locker, use the gum to get detention, and then use the stink bomb to get rid of the teacher.