Getting the Red Key (19)

Secret Area: Use a Jetpack to ascend the building's side. Enter a false wall at the top. Inside, carefully place a Pipebomb and detonate it from a distance to destroy numerous canisters. Collect the spoils: a Devastator, RPG, and Pipebomb. This secret area also provides access to a later part of the level.

Comedy Club: Enter through the window where a Pig Cop was previously firing. Inside, you'll face an initial Pig Cop, followed by three Captains and four Troopers around the corner. Grab a Shotgun and Large Medikit from behind the bar. On a table near the stage, find Chaingun Cannon Ammo. Break a trashcan near the stage to reveal another Large Medikit. Activate the switch on the opposite side of the room.

Back Outside: Upon exiting, be aware of a Commander and an Enforcer. Collect Shotgun Shells near the double doors. Prepare Pipebombs for the next room, which contains six Enforcers. Use Pipebombs to defeat them, then collect the rewards: the Red Key, Devastator, Holoduke, two Pistol Ammo clips (near and on a counter), Atomic Health, Freezer Ammo (in lockers), a box of Shotgun Shells (at the other side of the room), and a Small Medikit (in a trash can).

Flooded Area: Opening the next door leads to a ledge with a Pipebomb and a Small Medikit. A switch here raises the water level outside, allowing you to swim to a ledge across the way for Shotgun Shells. Enter the water and swim along the bottom, collecting a box of Shotgun Shells and a Small Medikit. Proceed through a small opening to emerge in the control room.