From the campfire, follow the path until you reach a small shack in the forest. Enter to find an opening in the ground. Mount the ladder and drop down to find a passageway partially submerged in water. Take the only exit here, then ascend the stairs at the end of the passageway. Turn left as you enter to see a pile of flammable trash; approach and burn it with Lara's torch. Find the relic on the table by the wall and the pry axe in the corner before obtaining a new objective: exit the bunker. Use the axe to get the door nearby its initial location open, and do the same for the next door. Keep moving forward until you reach a dead end; the rusty ladder here leads to a way out.
As Lara exits the bunker, she begins to hear voices. A cutscene plays before you're back in control...somewhat. Lara's foot is stuck in a bear trap, so the only option she has now is to defend against the incoming wolves using her bow and arrows. Time will slow down whenever a wolf pounces; shoot them in this time frame to survive. Once the attack is over, a cutscene will play and Lara ends up back at a campfire. Your next objective is to catch up with Whitman. Find the document on the table here, then begin to follow the marker and Whitman will call back. Head past the large gate and the bridge to come across another wolf attack. Afterward, keep following the marker to find a new campsite and rendezvous with Whitman.