Alright here the walkthrough for the next chapter. Chapter twelve : Surface Tension. This one is quite long chapter, so enjoy.
Once the door opens, you will finally be on the surface ready to help. Fight any soldiers nearby and travel down the road. You will see the dam in the distance. There will be many soldiers surrounding it. Travel onward to the dam. Neutralize the soldiers in any way you can. There are explosive barrels scattered around to make the job easier. Enter the parking lot to the dam and head straight forward over the water. A helicopter will appear and start shooting at you. Take cover from the chopper and fight it. It will soon fly away after taking damage. Move forward across the dam again while simultaneously fighting soldiers. Try to take the walkway to the right of the dam. The concrete walkway will collapse and send you plummeting into the water. Find the ladder at the back of the structure and climb up.
Throw the power switch and jump back into the water. There will be another ichthyosaur in the water. Kill it, then continue to the area where the water is bubbling. The current will sweep you into a new area. Swim away from the dam through the canyon. Get to the shore and find the pipes. Crouch through the left pipe and crawl through. You will come to a wall with a sign that says Lower Canal. move straight ahead.Take the ladder and drop down to the concrete ledge on the side of the cliff. When you reach the next ladder, climb up.
Be ready to fight multiple houndeyes. Head towards the building marked with a 2. Avoid the high voltage fence and take the road going through the mountain. Use the valve to open the gate. Fight the soldiers in the area ahead. Once they are dead, walk towards the building. To the left there will be a small control room. Use the button to open the access hatches. Kill the soldiers that will attack after. Travel towards the gate marked B and head in. Walk through the gorge to the minefield. At the entrance you can find a green box with unlimited grenades. Use the grenades to destroy the mines. Watch your step and make sure you destroy every mine in your path.
Move around the barbed wire and jump on the rocks. Use them to access the nearby ladder. Drop down and crawl through the pipe. Crouch through the pipes until you reach a cliff. Take a long leap to a rock below you on your left. Kill the soldiers on the cliff. Continue across the ledge while fighting soldiers. Eventually you will come to a broken catwalk. Kill the soldiers on the other side. Make a running jump to the piece of metal sticking out of the other side of the gap. Head into the control room for health. When you’re done, walk down the pipe to the structure. Descend from the structure while fighting soldiers. Use the catwalk at the bottom to reach the other side of the cliff.
Travel around the ledge until you come to a storage facility door. Press the button and wait for the door to open. Destroy the sentries in the room or avoid the red lasers.
Enter the small office and grab the missile launcher. The helicopter will return when you step outside. Use the rocks as cover while you battle the helicopter. The missiles are laser guided, so keep your crosshair on the helicopter. There are rocket supplies in the green box, so make sure you resupply. After enough hits with the missile launcher, the helicopter will go down.
Walk around the ledge until you reach a ladder. Climb up and continue your ascent up the cliff. You will reach more gaps in the catwalk.Jump across the catwalk debris until you reach the next ledge. There will be a pipe leading through the cliff. Crouch through all three pipes and climb up the next ladder.Walk into the gorge and into another set of pipes to your left. There are multiple directions you can go. In the middle, there is a large yard full of soldiers. Try to avoid them.
Go around the side and avoid gunfire. Swim around the area until soldiers throw explosive barrels at you