Quake II/Launch Command

Level objective
The objective for this level is to shut off the coolant to the CPU core.

Strategy
(Expand this section)

Shutting off the Coolant
When you operate the wheel valve, you will get the message "1 more to go...". Jump onto the roof of the entrance to the room, duck under the pipe and jump up to the wheel valve on the other side. Or, just drop down and use the other elevator. Turn the second valve to get the message "Sequence completed!" and, after quite a long pause, the message "Core CPU is no longer functional" and finally "Access now possible to launch system". You can now open the fourth door off the circular passage.

The Blackhole Generator Computers
So, leave this room by the way you came in and shoot down the Technician waiting outside. Go 180 degrees around the central column and through the door under the "LAUNCH SYSTEMS" sign, which now stands open. The passage takes you to the left, where you will meet a Gunner, and then to the right and to a door. Open the door and deal with the four Guards inside. You will get the message "destroy the computers". The computers are on the walls to the left and right. First, take a look through the bars at the far end of the room where you can see what we assume is the black hole generator merrily spinning away. OK, now shoot the computers (see Secrets, below, at this point). Take another look through the bars and ... it's gone! Your field computer, which previously showed "Destroy the blackhole generator", now shows "Primary unit objectives complete" and "Launch systems destroyed. Force field disabled.  Proceed to exit".

Secrets
This level has two (2) secrets:
 * 1) At the start of the level you find yourself before a large platform with some nested, spinning rings magnetically suspended above it between three towers — the black hole generator.  Get onto the platform by performing a rocket jump — back up to the platform and fire the rocket launcher while it is pointed at your feet.  Collect a BFG10K gun and various munitions on the far side of the platform.  Return easily via the ladder.
 * 2) At the end of the level, just as you enter the exit corridor previously blocked by a force field, notice the cracked transparency on the left wall.  Shoot it, jump through and dive to the bottom of the pool to collect various munitions.