LEGEND

A) Starting area. 
B) Control Room.
C) Zig-Zag Room.
D) Exit.
E) The switch on this pillar activates a secret door back in the Starting Area marked as (F) on the map. This secret door is a one-way door into the Courtyard. Upon entering the Courtyard, a section of wall lowers revealing room (B). This doesn’t count as a Secret. 
F) Secret door activated by the switch marked as (E) on the map. This doesn’t count as a Secret. 
G) Secret 1
H) Secret 2
I) Secret Trigger that opens to Secret Area marked as (J) on the map after (H) has been activated in Exit Room.
J) Secret 3

WALKTHROUGH – FAST

It is recommended after clearing out area (A), to go left into area (K). If you wish to end the level early, you can press the switch on the pillar marked as (E) on the map, then run through the secret door marked as (F) on the map into the Courtyard. From there, exit the Courtyard through the southern tunnel and through the secret door marked as (G) on the map. Turn right and activate the Exit marked as (D) on the map. 

WALKTHROUGH – FULL

Otherwise, if you wish to clear all enemies, find all items and all secrets, then move from area (K) to area (B). Trip the Secret Trigger marked as (I) on the map and enter the Secret Area marked as (H) on the map. Then enter the Secret Area marked as (J) on the map. Finish by activating the Exit marked as (D) on the map. On the XBOX 360 (Collector’s Edition, not Arcade Edition), there is a secret area in the Courtyard. Head to the very east of the courtyard, and then follow the northern wall until it begins to bend northwest. Press on this section of the wall to be taken to the Xbox-exclusive secret level, E1M10: Sewers.

SECRETS – 3

1) Past the zig-zag area, there is a wall on the right that can be opened. It leads to the central courtyard with the mega armor. While you can access the area by using the switch in the room left of the entrance, the secret door at the nukage pit counts as the secret.
2) Near the exit room, walk to where the ceiling changed height, and backtrack to the zig-zag area. A platform has lowered, providing access to the Secret Area maked as (H) on the map. This area contains a shotgun, medikit and ammo.
3) When you cross the start of the zig-zag area, a lift in the prior secret will lower marked as (J) on the map. Step on the one-way lift for the secret. It leads to a secret area containing armour bonuses and ammo, as well as a view of the nukage pit to hide from other players.

LEGEND

A) Starting area.
B) Upstairs Room.
C) Elevator.
D) Exit.
E) Secret 1
F) Secret 2
G) Switch to activate Secret (H)
H) Secret Door activated by switch (G)
I) Secret 4
J) Chainsaw Room
K) Secret 5
L) Secret 3
M) Secret Lift
N) Secret 6

WALKTHROUGH – FAST

It is recommended to go to Secret Area marked as (E) on the map to get the Red Key in Area (F). Go through the Red Door on the West side of area (A) and up the stairs to the elevator marked as (E) on the map. Then head to (D), the Exit. 

WALKTHROUGH – FULL

Otherwise, if you wish to clear all enemies, find all items and all secrets, then clear out Area (A) on the map, then open Secret Area marked as (E) on the map and clear out the East side of the map. Then move through the Red Door on click on the switch marked as (G) on the map. Then head South and clear out all enemies and find the 2 Secret Rooms. Then move up North to Secret Area (K), then area (J). Take (M) to the Elevator marked as (C) on the map, first heading to Secret Area (N), Finish at the Exit in Area (D). 

SECRETS – 6

1) In the first room, there is a hidden room in the eastern part of the middle section. Search the east wall to open a door marked as (E) on the map to reveal a backpack, green armor and a switch. 
2) After flipping the switch in the first secret, the northern corridor to the red key area will open to the outside marked as (F) on the map. This reveals a chaingun and a supercharge. 
3) Head through the red key door. In the south-west section of the map (after you flip the switch in the nukage pit marked as (G) on the map), go to the south-east section of the maze. Open a secret door to reveal a backpack marked as (L) on the map. 
4) Head to the south-west section of the maze marked as (I) on the map. Shoot the west wall to open it, and enter. This eventually leads to a chainsaw, but stepping on the first door counts this secret. 
5) In the stairs within the previous secret, look for a secret door on the right wall, just as it makes a turn to the west marked as (K) on the map.
6) After climbing the stairs inside the red door, cross the serpentine path through the slime pit. Look for a secret door on the left hand wall, just before the elevator marked as (N) on the map. 

LEGEND

A) Starting area.
B) Oval Office.
C) Blue Key.
D) Grand Stairs.
E) Exit Area.
F) Switch
G) Trigger
H) Secret 2
I) Secret 3
J) Secret Exit
K) Sniper hole to Secret Exit.
L) Secret 5
M) Trigger for (L)
N) Yellow Door
O) Secret 1
P) Secret 4
Q) Secret 6
R) Ambush
S) Elevator
T) Yellow Key.
U) Yellow Room.
V) Secret Trigger for (O)

WALKTHROUGH – FAST

There are 2 exits from this level. One is the main Exit to E1M4: Command Control and the other is a Secret Exit that takes the player to E1M9: Military Base, which is the final map. To access the Secret Exit, you will need to activate the switch at (I). This will raise the Bridge to (J) and (Q). You won’t need the Yellow or Blue key unless you are accessing the normal exit. 

WALKTHROUGH – FULL

Otherwise, if you wish to clear all enemies, find all items and all secrets, then clear out Area (A) on the map, then head to the Northwestern door and follow the info in the Secrets below. Collect the Yellow Key, then head north to (B) and (C) to collect the Blue Key. Then head through the Blue door off the Starting Area. There is a secret door (L) activated by (M) to access the Yellow Door (N) and the Yellow Area (U). Then you can decide if you wish to exit through the Secret Exit (Q) or the normal exit (E). The bridge to the Secret Area in the Starting Area is activated by (I). 

SECRETS – 7

1. In the yellow key area, quickly run up the stairs marked as (V) on the map and head to the left. Quickly reach the lowered platform marked as (O) on the map to reach a supercharge; the secret involves taking one step.
2. In the yellow key area, quickly run up the stairs and head to the right. Quickly reach the lowered platform marked as (H) on the map and enter to reach a rocket launcher. In both of the above two secrets, the trigger to lower the platform is the highest-most step on the first set of stairs.
3. From the right secret near the yellow key area, dive into the nukage and head to the right to reach a backpack and medikit marked as (I) on the map. The switch will raise the bridge in the nukage area at the start.
4. From the north-west nukage secret, exit by the secret door marked as (P) on the map. This leads to a chaingun.
5. Behind the blue key door, activate (L) by triggering (M). Open it to collect a chainsaw and other items. If you have the yellow key, you can also obtain a supercharge and blue armor marked as (U) on the map.
6. Cross the slime pit at the start of the map; this leads to the secret exit.
7. Use the north wall in the secret exit to reach a box of rockets. Don’t forget this final Secret before exiting the level.