My own method.
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 The method to the part of the game where you are knocked out by
the tranquiliser dart and you wake up in the lab without any
weapons or health packs. 

  First of all when you wake up and all the doors are locked, go
over to the corner of the room where the power junction box is
and fix it to switch the power back on. once the power is back on
you can open a couple of the doors. Secondly, go round that room
and access any computers that are in there and get any
imformation. 

  There are two areas you can go to now the power is back on, you
can either go into the main corridor where you can see the large
walker Thing walking around or you can go into the darker room
which has 2 mini Things in there. The best way to go is out into
the main corridor. Look through the window until the large Thing
goes round the corner and out of your sight. 

  Now as quick as you can open the door and get the machine gun
ammo off the dead guy on the floor thats opposite you as soon as
you open the door. Once you have picked it up turn left and go to
the room which has the biohazard sign on the door. Quickley go
into that room by pressing the switch on the wall to open the
door. If there is a junction box which needs to be fixed to open
that door you might have to run back into the room where you
started so the Thing doesn't get you and remember to close the
door. 

  Do the same as before where you wait until the Thing goes out
of site and when it does, run out into the corridor again and go
into the room on the left with the biohazard sign. Once in there
close the door. In that room is a guy with a machine gun. He says
get him some ammo and he'll follow you. As you already have the
ammo off the dead bloke, give it all to him. He will now trust
you and follow you. Although, you have to take it off him and he
does'nt follow you now until you give it back.

 Now run back into the room where you started, close the door
with the guy in and close the door to the room you're gonna go in
and go into the dark room where there are two mini things. Kill
them and then go into the next room where there is an engineer.
He trusts you a bit so get him to follow you back to the room
with the other guy in. and tell them to both wait in there.   
  
 Now is a tricky bit. You have to lure the big Thing in the
corridor into the room where you started. To do this go back into
the corridor and shut the door so that the guy with the MG and
the engineer is safe. Now when the Thing sees you run into the
room where you started behind the table so that the Thing runs
there aswell. When its behind the table as quick as you can run
back out into the corridor and close the door so the Thing is
trapped in that room. You have to be very quick on that part as
the Thing is fast. 

  Now with it trapped in the room, go and get the bloke with the
MG to follow you (give him his gun back), and get the engineer to
fix the armoury panel which is the 1st room on your left in the
corridor from the room with the biohazard sign on it. Once you're
in you'll notice the security gate is sparking and the lasers are
flashing, just run straight through them into the armoury and
take the machine gun and flame gun and grenades as well as all
the ammo. Assign anything necesary but dont give any of the
blokes the Flame gun. The MG ammo box in that room is an
unlimited one. Take as much as you can and then give all of your
ammo to the guy with you and then take as much as you can again
so you both have full ammo. 
 
  Now tell the guys to wait there and you go into the main
corridor and shoot the Thing through the window on the corner or
the wall with the machine gun, carefull as a small Thing jumps
out of the vent. Now with the Large Thing on low health, go and
open the door and flame him good. You don't HAVE to do that but
if you like killing Things do it.
  Collect anything around that area like papers or magazines. Now
go back to the armoury and grab whatever you can and get both of
the mem to follow you. 

  Now run through the corridor and go through the first room on
your left where there is a save point in a branching off room.
Now go back into the main corridor and go into the room where a
guy is standing up against the door. Don't be fooled by his
innocent medic clothing. He is a Thing and bursts out when you
open the door, get ready to blast him and flame him good. When
he's down go into the room with the laser security beams. There
are four switches and after it goes into the FMV press the 4th
and second switch in that order which turns them off. The rest is
pretty simple from there. 

 A final word of advice, kepp the engineer alive and be careful
of the people in the cells. Phew that was long, hope it helps. 

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