Press it to find a small room with an extra life (a blue ball with a picture of your face on it). There is one more secret however on the left wall. Inside this passage is another level exit (this takes you to the secret level - level 10). On the wall immediately opposite the medkit is another secret passage. Press it to reveal a secret area with a medkit on the left. Instead there is a secret passage on the wall to the right of the exit in the corner. These are the last of the enemies on the level. Go back to the other door in this area, and open it to find two guards (kills 17/18 and 18/18) and the level exit. Open the door nearest that single piece of treasure to find a small room with a medkit. There is also a single treasure cup in one of the cubby holes in this area (22/23). Firing a single shot in this area will trigger him (you'll hear him talk once you fire a shot). Inside is a fairly large area with a single guard patrolling. Go through this door and find two patrolling guards (kills 14/18 and 15/18).ДЄfter killing them, go to the door to the north and open it. Go through the door in the previous room to find an empty room with a door at the far end. Press A on this to reveal another secret area containing another 7 pieces of treasure (21/23) and a bunch of ammo. Also in this room there is a portrait of Hitler on the wall between two plants. Also in this room are 7 pieces of treasure (14/23).

Proceed through the next door to find 2 more guards. There are two in here, kill them both for kills 10/18 and 11/18. Open it, walk inside, fire a single shot and you'll hear some Nazi's get 'activated'. Go through the door on the right first to find a small room containing 7 pieces of treasure (7/23), collect all the treasure then proceed to the other door. In the next room there are two guards (kills 10/18 and 11/18), and doors to your left and right. Go into the newly revealed area to find a machine gun and some health. After you kill him walk up to the painting of a bird on a statue and press A (use) to reveal a secret area and pop the following achievement: On the left side there is a single guard hiding in a cubby hole. Note that it looks like there are paths on the left and right. Inside there will be wooden walls and one guard at the far end who sees you, kill him for kill 8/18. Retreat back to the big larger room and open the door between the two wooden panels. Retreat back and open the other door to find a room with 1 guard and 1 dog. Go to the one on the right to find a room with two dogs in it, kill them both (kills 4/18 and 5/18). One at the end of the pathway to the right and one in front of you. Inside this room you'll find two guards patrolling, kill them both (kills 2/18 and 3/18). Continue on to the door at the far end & open it to find a large open room with a door between two wooden panels straight ahead, and a single door to the right between two blue rock walls. Retreat back and go through the door to the north and enter a larger room. To your right there's an open hallway, go down here and kill the single guard on your left (kill 1/18). You start in a room, go forward and through the door. I'll give a bit more detailed of a walkthrough on this level specifically to make sure you get everything, subsequent levels I'll largely defer to the online maps for you to refer to. This first level is a bit special in that you'll want to get all the treasure, kill all the enemies, and find at least one secret on it.

Original wolfenstein 3d