[8.4]. Mission 4 - Area 51: Infiltration

Shut down air intercept radar: Immediately strafe left behind cover (press the cover button to crouch behind walls or objects) and eliminate the guards. Collect their MagSec weapons and ammo. Destroy the automatic machine gun down the path opposite the helipad using your MagSec. Continue past it and around the corner, destroying the machine gun on your left. Proceed forward, turn right, and eliminate the two targets near the large tower. Run past the tower, eliminating any guards emerging from the tunnel. If you have grenades, toss one through the hole in the fence to the left of the tunnel onto the snow to detonate mines and retrieve the Rocket Launcher on the helipad. Take the Rocket Launcher and ascend the tower. At the top, press the red button to open the gate, then descend and enter the tunnel. At the tunnel's end, eliminate the guards and the machine gun to your left. Return to the helipad where you obtained the Rocket Launcher. Toss a grenade towards the cliff to detonate any remaining mines. Veer left from the helipad to find a small opening in the steel wall; crouch and enter. Towards the end of this passage, find and take armor. Exit the tunnel, kill the guard outside, and follow the path to its end. Turn right and destroy the two machine guns on the wall. Turn around, pass the hole in the wall on your right, and turn left. Proceed down the side of the wall, turn left again at the end, and destroy the machine gun on the wall above you. Turn around, descend the ladder, and enter the hole in the ground. Enter the silver door, veer right, and proceed to the back of the room. Plant your Explosives on the Computer Panel. Quickly exit the room and ascend the ladder again.

Gain entrance to hangar lift: At the top, move forward and shoot the guard in the center of the large open area. Collect the key card he drops. Go to the right of where the guard was standing, next to the large roll-up gates, and use the key-reader on the left. Press B to activate it and open the gates. Enter and proceed to the elevator on the left. Exit the elevator and eliminate the guards with your Dragon, being cautious of those with grenades. Your second objective will be complete upon successfully exiting the elevator.

Make contact with CI spy: Run to the ramp at the back of the room and ascend it. Follow the path at the top to the elevator at the end. Exit the elevator and continue along the path until you reach another ramp. Eliminate any guards encountered. Run underneath the ramp and through the open door to meet the CI spy and finish the first part of Mission 4.