Your primary objective in this level is to destroy a computer core. You'll also need to find and destroy some power conduits to disable security trip-beams and forcefields.
First rooms[edit]
To your right in the first room is a console that has a remote control for a patrol eye. This is the first of a few examples of remote-controllable enemies you'll encounter in the game. There's no purpose to this one other than something to play with, but you can fly it around much of the level and get an idea of the layout. It will initially be next to the computer core you need to destroy. Also in this room is a switch shaped like a red diamond. There are several throughout the level: they open and reset the security doors you'll come across shortly. Blue = tripped; red = reset.
The door ahead to the Control Room is powered down, so take the door on your left, go up the overlook and hit the switch to power up the door. Also, use the Mazrium platform to get to the air duct, where there's ammo. In the back room up here you'll see a power conduit protected by a forcefield. You'll need to disable the forcefield and then destroy the conduit. Also in this room, look for a section of wall next to the doorway that's brighter than the rest: there's a secret area inside, with a sneak peek at another room beyond.
Control Room areas[edit]
Go back down to the first room and take the Control Room door you just powered up. You'll see an example of the security trip-beams that are throughout the level. If you cross the beams, the security door just ahead will close. You'll also get some company in the form of HSDs (hover security droids), but only the first time you do this.
The beams prevent further access this way, so take the side door to the Control Room area: a tall darkish room with some sort of machine in the middle. (There's an Invulnerable hanging from a chain you can jump for.) Take the lift up to the platforms, then take the lift in the nook in the wall down to a second tall room with a power conduit. Destroy the conduit, and the forcefield protecting the power conduit near the level entrance will be deactivated. There's also a set of Low-Grav Boots where the conduit was. You'll need these so grab them. Your objective in here is completed, but there's lots of ammo inside that upper side room and the air ducts inside the two vents. In the ducts above the platforms, turn left and shoot the wall at the end to open additional secret ductwork (note the rubble).
Concourse[edit]
Go now back to that first power conduit and destroy it to deactivate the security beams that were in the way. Reset the doors with the diamond switch if necessary, and continue up the main concourse. See that shootable switch on the wall? Look on the opposite side for the recessed floor-to-ceiling lights, stand on the bright patch of floor in front of the lights and shoot the switch. This is a lift down to a secret passage leading to the tall room where you were earlier. (In fact, when the trip-beams were on you could make a run for the security door and get past it before it closed. If you tried this, this secret passage is the way out.)
The CPU Corridor door at the end of the concourse is unpowered, so take the other one off to your right to another room with overlook like the one by the level entrance, and another power conduit inside another forcefield. Hit the switch to power the CPU Corridor door out on the concourse. (Also, stand on the Mazrium platform nearby, shoot the switch above the door and ride the platform over, and get another set of Low-Grav Boots behind the glass to your right.) ==CPU Corridor and core Go through the CPU Corridor door, which leads to a second concourse. Take the passage just to your left up to an overlook between the two concourses--the CPU Corridor. Next to the larger of the two windows is a bright section of wall. There's a secret area inside. Go through the door at the far end, and take the teleporter inside the next room to a control room next to the CPU core. Hit the big switch to open the core. Go to the core and repeatedly shoot at the vertical-striped column in the center until the core collapses.
Your primary mission in this level is now completed. A security door isolated the room when you destroyed the core. Look for a panel with safety stripes and take the teleporter inside, which goes back to the control room. You can reopen the security door with the diamond switch. There's one more set of trip-beams you need to deactivate in order to exit the level. Go back to that side room where you powered the CPU Corridor door. Shutting down the CPU disabled the force field blocking the power conduit in the back room. Shoot the conduit to take out that last set of trip-beams in the second concourse.
More secret areas[edit]
Your tasks in this level are now completed. The exit is the transport tube upstairs in the exit room past the far end of the second concourse. (Note the "exit" symbols above the door.) But before you leave, there are several more secret areas left. Near the ramp to the CPU Corridor are two compartments high on the wall that are now open. Use Low-Grav Boots, and collect the Secret Level Access Keycard from one compartment, and another set of Low-Grav Boots from the other. Nearby, look for a big discolored patch in an inset area next to a red flashing symbol up on the wall. There's a big secret area behind here. Next to the door to the exit room is a destroyed door. Shoot the crystal-egg pylon inside here for another secret. Finally, go through the air vent next to the transport tube in the exit room. Before shooting the crates or barrels, use them to reach the ammo on the ledges and caved-in section. (This is the room you could see into earlier from the secret area near the first power node/forcefield.) When you're finished, enter the transport tube to exit the level.