Help on Firewarrior

[Were-Sandwich]

I'm stuck on Firewarrior. The level 'Power House'. After I get past the bit with the indestructible turrets, and take out the Marine thats guarding the door, I go through the door, and it locks behind me. I take out the two marines at the end of the corridor by sniping them with pulse carbine grenades and Plasma Gun shots.

The door behind them remains locked after I kill both of them, adn I can't find a switch anywhere after scouring the area, and I'm locked in, so I cna't go back through the level to look for anything.

I ask you guys because if I looked it up on a walkthrough the temptation would be too great to look up how to beat the entire game.

[Crazy Owl]

Well I havent played Fire warrior in years but If someone reads the guide for you I guess there won't be any temptation for you to read on.
I think this is the part your asking about.
Kais is now in a long hallway with some ceiling mounted guns. The guns are not
active until you fire at them, DON'T FIRE AT THEM. Setting them off will cause
you to fail the SECRET OBJECTIVE which is to not set off any sentry alarms in
the level. There is another hallway similar to this one later on, you can't
set off either alarm. At the far end of the hallway is a space marine guarding
the door you need to enter, don't attack him either, this will also set off the
alarm. Instead, see that little hole on the wall on the left? And see those
barrels by the door? Climb into the hole and shoot the barrels. This will
attract the space marine without setting off the alarm. Walk down the secret
hallway you are in and turn right, viola! You are at the next door and the
space marine is at the other end of the hallway.

Enter this door and you'll be in a strange room. To your left is a hole. This
hole leads to a crawl space, BUT part of the crawl space is missing. You must
throw a switch to complete your path. The switch is in the next part of the
room and is guarded by 2 space marines. Pull out the old bolter. Walk forward
a little bit and the space marines will spring into action. To beat them
simply run up to and stand next to the door they are guarding. For some reason
their pulse gun shots are attracted to the door and will not hit you! Give
each of them a face full of bolter while they try helplessly to fire on you.
When they are dead grab both of the plasma guns. Now throw the switch (it's in
between the two parts of the room on the wall), and climb into the hole.

[Were-Sandwich]

Thank you very much. I'm gonna go on Firewarrior now.