Once you transport to Norad VI, Alpha Sector, each time you will be "greeted" by robot Poseidon. You hear a warning about a problem in the ventilation system, and your character's breath indicates some problem: the air is poisoned, so you have 75 seconds to act. If you have the Oxygen Mask from Mars activate the filter. This is done automatically in easy mode.
Turn right and access the screen of the gas intake & dispensing station (5). Remove the sleeping gas contaminate from the air supply. Now you are safe from the sleeping gas but he AI warns you that you must put it back or else you can't use Pegasus. Put on the Nitrogen Canister and select "Dispense Mode" on the screen and choose N. Your canister now will be filled with Nitrogen. Repeat now with the Argon canister (press Ar) (5) and the Oxygen Mask from Mars (press O) (5). Replace with the Gas Canister and choose Intake for you to be able to exit the room. An alternate way to defend yourself from the sleeping gas is to activate the filter of the Oxygen Mask (it doesn't have to be filled, but you will need the oxygen later anyway).
Notice that if you exit the room while the sleeping gas is still active (or you haven't activated the mask filter) means you will fall unconscious and will be captured.
Now exit the room, turn left to the E to see the unconscious operator (5) and proceed, through the door. In the next room, close up to the panel and press the down/decrease button until you equilize the pressure (5). This is done automatically in easy mode. Enter the Sub Bay 3 elevator, turn right, access the control and descend.
Sub Bay 3
Continue your way to the E and enter a small control room. Access the screen and intercept the report from between a submarine and the control: the base is under Red Alert and still trying to find out what is happening.
Turn to the right and close up to the screens. Select "Launch Prep" (5) and if you want you can test the claw by activating it (5). Now zoom out. Exit the control room and return to the bay. Turn to the left and step on the access platform A4. The attack sub (DefSub 4) is lowered and you board it (5).
Now enjoy the cutscene where you pilot the submarine to Delta Sector. When not in easy mode, you'll have to avoid missiles by correctly pressing left or right; the correct answer is left to all but one of the decision points, the one exception being the one following two torpedoes and a shipwreck. You receive some transmissions as the command are alerted by the unauthorised launch, considering you a terrorist infiltrator, and DefSub 62 attempts to stop you with torpedoes, however you don't suffer more than some damage, and make your way to Delta Sector (10).
In the Delta Sector you can exit the bay and proceed to the corridor and see Poseidon through the door window he is typing something (5). You can't stop him.
What you can do is (from the console room) follow the corridor and turn left to the security door. To get through you need to activate the retinal chip (5) Not needed in easy mode. You now have to cancel the launch procedures initiated by Poseidon. It's actually a race of time. Geographic knowledge helps, until you cancel all (10). This minigame is solved automatically in easy mode. If you take too long to locate a spot and cancel the launch, you will fail your mission and you must restore (or replay it).
The locations you must locate are
- Honolulu (2 minutes to cancel before launch)
- Dublin (1m50s to cancel)
- Adis Abeba
- San Antonio
- Madrid (30s to cancel)
Now Poseidon will be furious. Go buck to the bay control room and Poseidon will come after you. There are two ways to defeat him: one is to zoom to the pressure controls of the room on the door. Poseidon is hitting the door. You have limited time to act (5 punches on the door) before he breaks in and kills you. Increase the pressure to the highest point and the robot will be crushed.
For the non-violent solution (and Gandhi points), go to the controls and use the mechanical claw to grab it. Move the claw down, press grab, then move the claw right, then press spin. If you select a wrong option, Poseidon will find an opportunity to break in.
In both cases the android will be crushed (10) (you don't have to do anything in the easy mode). Collect the biochips from his head (10). The most important are the shield biochip (can be used at WSC catwalk, Morimoto reactor room, and Caldoria rooftop) and of course the opmem biochip with his orders from Elliot Sinclair; and transport out (10).