Originally called the "Megg":
Choose the legendary difficulty. Then right at the start when you exit
the cryo-tube, run around the corner and you should see a stack of barrels
with a coloured stripe going round them. Get on top of the yellow striped
one and stand there for approx. 10 seconds. To get on top, you have to
crouch at the top of your jump to reach a little more height. Then run down
through the shield generator and exit the room. Watch the scientist guy get
killed by the explosion from the door, then run all the way to captain keyes
without slowing down to do something. Just run straight to him. Once you
have the pistol get an assault rifle and run back to the bridge. Kill
anybody on the bridge for some marines to run out and kill you. You can't
kill these so use the assault rifle to stun them and stop them shooting. If
you done everything right the door they came from should be open. Run in
their, the marines won't come in so you'll be safe. Go to the end of the
room and look at the ceiling. You'll see the letter "M" made of bullet holes
inside a heart-shaped blood stain.