This mission took me forever to figure out. There is a first area (entrance), a second area, a third area (with computers, etc), and fourth area (temple). You have to make it all the way through all the areas without being seen and into the second floor of the temple in under 10:00. Here's what you do.
Immediately lay flat and snipe the guard walking on the catwalk in the 3rd area (nearest your position). He falls off the platform. Then, immediately snipe the two guards standing in the corner on Temple catwalk. Take the guy on the left then the guy on the right.
Now, snipe the guard who is standing on the 3rd area catwalk underneath the tower with the wire which leads to the second floor of the Temple. You'll see his faint outline through the leaves of the trees.
Now, snipe the guard standing inside the building in the 3rd area where you disable the alarm. You'll see his faint red outline beside the tree on the right. Drill him!
Now, shoot a single bullet through the door leading from the 2nd area into the 3rd area. This causes the 3 guards standing by that door to open the door and enter the 2nd area to investigate.
Now, snipe the guard facing the wall in the back of the 2nd area behind the tent. Snipe the guard on the right inside the tent. This causes the guard on the left in the tent to run to turn on the alarm. Put one square into his chest as he exits the tent!
Now, aim into the 1st area and snipe the guard on the catwalk in the back corner holding the RPG. That was 10 clean and easy shots! RELOAD!
Now, snipe the guard on the 1st area manning the machine gun above the front door. You'll see a small portion of his back. Drill him!
The alarm sounds!
Now, snipe the guard standing above the door between the 1st area and the 2nd area. Try to get the guard with the RPG as he runs down the stairs.
Now it gets crazy. You have to snipe ALL the guards in the 2nd area without sniping the guard in the 2nd area standing in front of the metal shack. For some reason, if you snipe him then the alarm mysteriously sounds whenever you enter the second area.
You also have to snipe both pairs of snipers in the two front towers. Hint: You can kill them both with a single shot if you aim so you hit a small piece of each guy.
Check your map computer. Make sure there are no guards you missed.
When you are done, there should be two guards in the middle of the 1st area, one in front of the shack in the 2nd area, and two guys above the main gate. If you see anybody else, pick them off before getting up!
You need to save 3 sniper bullets. If you're out of ammo, start over.
Now, get up and run way to your left and lay flat on the edge of a small hill where you can see the 2 snipers above the main gate. Pick them both off.
Now, run to the gate and unlock it. Lay flat and crawl to a position behind the truck so the one guard standing near the alarm is visible from underneath the truck. Look through your heat-vision scope and aim directly at the one guard by the alarm. If you're in the right position, the other patrolling guard will cross right into your scope. Fire your last shot when you've got both guards in your sites and both will go down with a single shot! You have to take both these guys out before one of them hits the alarm.
The only guy still alive should be the guard in front of the metal shack.
Get up and toss the sniper rifle. Click your silenced machine gun to single shot. Run toward the door leading into the 2nd area and up the stairs to the right. Run over to the cable and slide down the cable to the top of the metal shack. The guard standing there starts to walk toward the alarm. When his back is facing you, shoot 2 or 3 rounds straight into his back. When he goes down, RUN off the shack and to the 3rd area door and unlock it.
Open the door and RUN to your right and jump over the corner of the truck between the truck and the fence. Run around the right side of the building with the alarm computer (you already sniped the guard inside). Hide behind the last wooden post and when the alarm turns away, step up to the door and open it. Activate the computer. If you get to the last wooden post and the alarm is already turned away then don't hesitate! Open the door while the opportunity is there.
Now, crouch walk out of there and run back the way you came. You are going to run around to the back corner of the building with the computer which activates the tower. Get to the right side of the building with the computer and crouchwalk around to the door, unlock it, and activate the computer.
Now, crouch walk out the door to your left and head straight for the fence by the tower. You can walk most of the way but be careful. Open the fence and climb the tower as fast as you can. Slide down the cable.
Now, here's the trick. When you exit the cable, immediately lay flat in the direction of the catwalk. You are going to belly flop off the top platform down to the lower platform. Then, belly flop off down to the tile-side of the wall below. Don't belly flop all the way down to the grass below because you'll end up with damage. Once on the tile, belly flop from there to the grass below. You won't get hurt.
Be careful because there are guards still running around crazy in that 4th area trying to figure out how the two guys on the top of the Temple got killed.
At this point, you're now in the 4th area laying flat on the grass behind the two guards facing away from you. Check your map computer to get an idea where everybody is.
Crouch walk toward the Temple stairs and get up onto the ground floor by the temple front door. You can run part of the distance if there are no guards nearby. Now run all the way around the rightside of the temple to the back corner by the wooden platform leading up to the second floor. Lay flat just as you get to that rear corner by the wooden planks. Crawl up the planks to the top. I've run up the planks but I got killed three times in a row just as I hit the top plank! Once on the top plank, RUN towards the back door and unlock it. Mission accomplished!
Practice sniping. You can kill 10 guys right away in under a half minute. If you're good then you'll be able to clear out the rest of the guards running around quickly and the pairs of snipers in the towers. Save 3 bullets!
Remember to leave the guard alive standing in front of the shack in the 2nd area. And, once inside the 3rd area, you have to act quickly and decisively to get into both buildings, activate both computers, and get up on top of the tower and into the 4th area. Once in the 4th area, quickly check your map computer then get moving!
I did this mission in 9:16 without being seen, 100% health, and 100% accuracy. It's tough to complete this mission in under 10 minutes but it can be done.