Lara's next objective will be to continue up the mountain in order to rendezvous with Roth. Loot the men before climbing the recently dropped ladder to make it to higher ground. Follow the path up the steps to discover the Mountain Temple camp, where you can save and upgrade. Before moving on past the bridge, find the nook to the right of it, by the waterfall. Here you will find a document, a journal entry which once belonged to a madman. Head back out, cross the bridge, and take cover as Lara approaches the top of the stairs. Some enemies will be standing around; you'll be able to distract them by shooting an arrow at the wall. Take this opportunity to get some easy head shots, then continue up the stairs and climb into the building at the top of the stairs. A pile of trash sits in Lara's way; shoot the lantern hanging above it to set it on fire and clear the path. Crawl forward and Lara will eventually come across another enemy. Here, Lara will be able to pull off a stealth kill as he passes.
Lara will be able to kill a couple of men like this, until you get a good view of a couple of flashlight-wearing gunmen walking around on higher ground. Climb up the wall to the left and take them down with a few arrows. Once they're out of the way, another gunman will target Lara from a ledge. Shoot him and the walls will begin to crumble as reinforcements arrive. Follow the path and jump across the ledge as you loot fallen gunmen. Turn left at the wall and use the zip line to land at a safer location. Before pressing forward, access the document to the right of the landing. Move a bit back from here, then right to find a fork between a climbable wall on the left and a narrow path on the right. Head right first. Light a torch and enter an opening to the left to find a box containing a relic, then return to the wall. Climb it and light the flammable material nearby. Salvage the material and move up the stairs, then hop onto the rooftop next to them. Find the opening to obtain another relic. Drop back down and return to the zip line landing. Walk past the gate to move on. Squeeze between the walls and Lara will boost herself up them. Advance up to solid ground and follow the path to activate a scene and obtain a new camp as Lara finally reunites with Roth.