The player starts the mission on a MH-6 Little Bird helicopter, as you and the other Little Birds move closer and closer to the gulag (a Russian word for a remote prison camp) while F-15s destroy a SAM (surface-to-air missile) site on a nearby ridge. As your Little Bird flies over the gulag, snipe the soldiers on the towers. Your main concerns are the enemies armed with RPGs, but they should be easy to take out. Once the towers are taken care of, the helicopters land and you will fight enemies on foot. There are several enemies on the higher floors, but a Little Bird will help clear them out. Walk through the courtyard until you reach the prison entrance. It is a good idea to replace your M14 EBR since everything beyond this point is almost exclusively close-quarters fighting.
Eventually the player will come across a control room, and Ghost will take control. The player will fight their way counterclockwise around the Prison while Ghost unlocks the doors in front of you. Descend down the corridor until you reach a square room in the center of the prison ring that contains a weapons rack. Enemies will encircle you, so stay crouched and avoid as much gunfire as possible until Ghost unlocks the door ahead. Grab a riot shield (unless you want bullets all over your body) and follow Soap down the hall. Soap will reach a rappel point, where you can swap out the riot shield for another weapon. Follow Soap into a dark hallway and equip your night-vision goggles. At the end of the hall remove them and follow Soap to a pipe room. Wait until he throws his flash-bang and take out the enemies behind the pipes. On the other side of those pipes, there is a hallway with three enemies behind a right turn. It is easiest to roll a grenade or flash-bang under the pipes down to their level in order to get past them. There will be a breaching position up ahead; plant the charge and kill as many enemies as you can in the bullet-time slow motion sequence.
In this first chamber, there will be some enemies on the floor, and some above you on either side. The latter are hidden behind the walls but can be spotted by their laser sights. Advance to the second chamber once you have cleared out the first, and several shielded enemies will run at you. If you still have your M4A1 Grenadier, or simply grenades, use them to take out the shielded enemies. You do not have to completely clear the last room; simply kill enough enemies to safely run past them and jump into the hole in the floor. Follow Soap to the final breaching position, where Prisoner 627 (Captain Price) is being kept. He is seen choking one of your enemies, and then punches Roach.
Price/Prisoner 627 then points his gun at Roach, but then Soap points his gun to Price's head before they both realize their true identities. After this scene, the U.S. Navy will start bombing the area. Quickly follow your squadmates to safety. If you run too far ahead of them it's very easy to get lost and killed by the falling debris. At some point, you are to turn around (you can see an enemy running too but and follow a different path while the debris chases you. You all reach a dead end, and Roach gets knocked out. When he comes to, Soap shoots a flare into the sky and a SPIE rig (zip line) is lowered down by a waiting helicopter. When prompted, approach the SPIE rig and attach your cable to be airlifted to safety. Then sit back and watch the Navy bombard the Gulag to oblivion.
Intel
Intel No 1 Before entering the arch gate with 2 red lights. Second floor, facing South-East.
Intel No 2 Inside "Control Room", where Ghost is using the laptop.
Intel No 3 On 2nd sub-level, North-East, in cell "327".
Intel No 4 After finding prisoner 627, turn left, on top of a desk.
