Call of Duty: Modern Warfare 2 Guide
Some players may find this level disturbing... There is no enemy intel here so you can always just skip to the next one.
Follow Makarov's lead as you make your way through the halls. If you don't want to shoot civillians yourself, by all means don't do it. You'll soon head outside and proceed through a tunnel. When you get outside, continue to follow Makarov's lead and kill the enemies. There's not a lot to it - switch over to your grenade launcher to make things easier on yourself. At the end of this mission, well, you'll see for yourself what happens.