There’s only two enemies in this first section, a dog (look for the shadow against the rail car) and the sniper. Tag them both so you can identify them easily. The sniper will periodically get bored and change position. To Ghost past both of them, simply RUN to the far side of the level from where you start, and get a rail car behind you and the dog. Avoid the sniper’s attention, and get onto the next rail car so you’re on the sniper’s level. Wait for him to get bored, then get up to where he is, and climb on his shack. Ghosted.
Getting through the next section undetected isn’t too tough either. Well, other than throwing the first sniper off the roof, that’s just kind of too good to pass up. But otherwise, wait for the first guard you see to start heading away from you and follow him. He’ll head back to the other sniper. Keep under cover to keep from the sniper detecting you, jump over the wall instead of going up the stairs, and head straight up the next wall. Use the ducts to avoid being spotted, then proceed to the far corner from where you came in, dropping to another roof. There are two more snipers on the next rooftop, but you can use the railings and the elevator shaft building to get around them. Drop off the far side again, do some shimmying, and you’ll be at the next marker.
There’s one guy in this room, but he’s easy to sneak past, and then you’re at the elevator shaft.
Drop down another rope, restock if you need to, and then you can go out the window or cut through the cloth. There’s seven guys in here total, including two or three in the next room, on the lower floor. There’s an office there. If you want to Ghost it, you’re going to have to use sleeping gas and sticky shockers and go slow. There’s too many guys and too much light to do anything else. Panthering or Assaulting is WAY easier here.
In the next area, you can avoid the guys easily enough, just keep to the shadows. Head over to the left and look for a marker for a laptop. Find a room above the marker and you’ll drop into a room with a guy holding a light, and the laptop. Outside are two regular guards and an armored one. I found it easier to take them all out than stealth it. Regardless, remember you need to get the drop on the armored guy or he’ll beat you down.
For the next part, stealth is beyond essential. Take a good scope on where everyone is before you start. Drop out of the window and shimmy to your left. You can go around the whole room this way. Get to where the truck is, go to the other side of it, and look for a pipe to climb. This will get you to the top of the truck. Head to the back end. You need to drop down undetected and hit X quickly to get into the truck. The easiest way to do that is with noisemakers elsewhere to cover your move.
Use the high path again to cross over to the exit and into the next section. Stock up and after the game saves, restart. There’s a very easy way to get the next HVT, but you have to be fast. Head through the window, run straight ahead, and slide into the darkness. The HVT will come to you. If you wait too long, he lights a fire and he can see you. Stash the body. From where you grabbed him, look the way he came. That’s the way out. There’s a heavily armored guy, follow him until you can drop through a hole in the floor.
Grab a pipe in the ceiling and look for the path to follow that goes to the left. That takes you close to your destination, then it’s just a quick run to the ladder that goes up. Into what looks like a hot zone.
After your reunion with Briggs, it’s a straightforward assault mission, but you only have your pistol. There are a LOT of commandos, but their red eyes make headshots and marking easy. Look for propane tanks in the first wave, they will help a lot.