Sacrificial Grounds level of Brutal Doom Question.

[Free Willy]

As you start the game, there is a room immediately to your right. When you go in there there one of the hallways ends with a compartment that has a power-up sphere and two little plasma ammo boxes. (graphic attached)

When you activate a switch somewhere the top panel goes up and the bottom panel goes down to allow access to the power-ups and ammo.  (red arrow depicting this)

 

Please inform me where the switch is. Thanks

[Diabolución]

Is that map actually Freedoom: Phase 2’s MAP28: Grim Redoubt? If so, you have to discover a really hidden switch and the secret with a berserk pack (unlocked by said switch), basically. Then, backtrack and pick up the goodies.

 

https://i.imgur.com/Mh1UEZl.png

https://i.imgur.com/1nr7zup.png

https://i.imgur.com/0KVEDS5.png

https://i.imgur.com/zVRFt2y.png

https://i.imgur.com/IZxpSKU.png

https://i.imgur.com/irRzVRi.png

https://i.imgur.com/V8W1XEK.png

 

[Free Willy]

Thanks DoomeroHispalense, that did the trick.