Getting the Red Key (16)

Begin in an outdoor clearing. Avoid staying still to prevent lightning strikes and fire from Mounted Guns.

To the side, climb a ledge to destroy a Mounted Gun in a cave. Collect the Pistol found there.

Descend and eliminate two Mounted Guns firing from below.

Locate a Large Medikit near the main facility doors.

SECRET 1: On a cliff, find a tiny ledge with a Pistol. Climb it to enter a cave containing Pipebombs and a Holoduke.

SECRET 2: From the main ledge facing the doors, walk right across a small bridge. A bloody handprint on the rock face opens a door under the bridge. Enter this cave to find Night Vision Goggles and Atomic Health.

Enter the facility through the main doors. Engage three Troopers (one with a Jetpack) and a fourth in a nearby hallway. Defeat the Captain behind the central column.

Near the computers at the entrance, find two Small Medikits. On a desk, collect a Pistol and Shotgun Shells. Be aware that using the tape recorder on the desk triggers an explosion.

Destroy the cracked large column in the room to reveal three Large Medikits.

Proceed to the Briefing Room to arm yourself before facing tougher enemies for the Red Key.

In the Briefing Room, defeat three Enforcers and a Trooper. Collect the Shotgun behind the desk, a Large Medikit behind the podium, Body Armor from the second locker from the left, and a Pistol and Large Medikit on top of the lockers. Find Pipebombs and Pistol Ammo on the middle counters.

Exit the Briefing Room through the door on the same wall as the lockers.

Advance down the hallway, fighting two Troopers.

Open the next door, which triggers three Sentry Drones. You can attempt to close the door to see if they destroy themselves.

In this room, find three Laser Tripbombs on a box, RPG Ammo in a corner, and two Microwave Expander Ammo and two Small Medikits inside a box to the left of the IMF logo on the wall.

Proceed to the elevator at the far end of this room to continue.