Cliffhanger - Call of Duty: Modern Warfare 2
Follow Captain MacTavish across the ledge and climb the ice. Take note that you can't just stop climbing at any point, or the ice will weaken, resulting in a long deadly fall. Leap over the gap like the Captain did, then follow him once again.
By using the heartbeat sensor you can spot targets from a distance. When MacTavish tells you to take out the guy on the left, do so on his mark. Of the next two patrols, take out the left guy once again. Proceed through the blizzard alone while Soap (MacTavish) stays behind to give you support in the form of Sniper Cover.
ENEMY INTEL #4:
Before entering the base to the south, first take out the handful of enemies nearby the entrance and explore the watchtower right in front of the entrance by going up the ladder. This intel is lying on the catwalk.
Video showing the location of Enemy Intel #4.
From here, make your way into the base and snipe guards all over the place while you sneak in. Carefully go around the containers as a truck approaches over the road, and proceed.
Make your way to the fueling station and plant the explosives. You'll now be out in the open, and your next destination is the sattelite on the west side of the area as indicated by your marker. Stay clear of any enemies and race your way over there. The Captain is already waiting for your arrival here.
ENEMY INTEL #5:
Before entering the building with MacTavish, head northwest and peek through the middle window of the hangar to your right, in which a jet is being fixed by two mechanics. Break the middle window and grab the Intel 'through' the window.;
Video showing the location of Enemy Intel #5.
Simply head upstairs to retrieve the ACS Module, then return to the Captain but don't show yourself. Instead, trigger the explosives you planted earlier and take out any remaining troops. With the majority of soldiers dispatched, follow the Captain and cover him at all times. Take out two snowmobiles after you reach the jeeps, then make a run for the cliff.
Quickly turn around and kill the soldiers that appear at the top of the hill, followed by taking out several snowmobiles. Hop onto one of these snowmobiles after downing all enemies, and race the course.
ENEMY INTEL #6:
Arguably the hardest piece of enemy Intel to find in the entire game, not in the least place since it's not picked up the usual way, but by driving over it during the snowmobile chase. To give you an indication where this tricky-to-spot Intel is located, it's about 1800 meters away from your goal, so it's relatively early during the course. Slow down considerably when you're about 1900 - 1850 meters away from your final destination, and you'll soon approach a small fence placed horizontally. As a landmark you should also be able to spot a hut on the hill to the right. If you pass this fence just barely to the left side, this intel is lying a few meters across if you just go straight ahead.
Video showing the location of Enemy Intel #6.
During the race it's obviously important to not bump into trees or large rocks along the way. Try to shoot as many enemy snowmobiles in front of you while racing to the end.