Metal Gear Solid: Peace Walker/Infiltrate the Crater Base

You are just outside the enemy's base in the heart of Irazú. Follow the road to the nukes' destination and keep them out of the enemy's hands.
 * Enter the enemy base.

Mission Prep
There are two prisoners and two soldiers who are consistently worth extracting, so bring the ★2 Fulton Recovery System. Bring the ★1 Love Box to exploit a shortcut and bypass extremely tight security. Bring the ★2 Mk.22 to perform Hold-Ups. The recently-acquired Desert Auscam will give you the best camouflage and you will need it. There are two randomly-distributed C-ranks among the soldiers in the fort, so consider bringing the ★1 Analyzer.

Los Cantos: Canyon
Visible up ahead is the caldera of Vólcan Irazú and the heart of the enemy operation. Between you and the enemy stronghold is a bridge, after which you will encounter an old fortress from the Costa Rican Civil War. This bridge is multi-leveled with the top level is broken; you'll have to go down to the lower level to cross then up some stairs to get to the other end. Be advised that your Auscam won't give you the high camo index you'll get in the next two areas, so be careful. There is one patroller along the bridge dead ahead. You are currently outside his visual range, so move straight ahead.



Run straight to point 1, regardless if Soldier A is watching. He'll turn around before you reach point 1. Go ahead and run straight off the edge down to the lower level. Move slightly west so you're clear of the pillars and you can see Soldier's C and B. You can ignore them entirely as you move north. Once you see the stairs to your left, start angling the camera in its direction. Stop at the base of the stairs.
 * 1. Run Off the Broken Edge



At the base of the stairs, count one-one-thousand, two-one-thousand to allow Soldier A - who you're likely unable to see - time to pass. After two seconds and a solid indication on the Surround Indicator that he has passed, crouch-stalk up the stairs. Once you have visual confirmation that Soldier A has passed (about halfway up the steps), then tap to stand straight up. Stalk the rest of the way up the stairs, then turn toward Soldier A.
 * 2. Wait for Soldier A; Climb the Stairs

With Soldier A facing the north, stalk to his left. Stalk your way over the edge to Soldier A's immediate left and allow yourself to fall. You'll automatically grab the ledge. Soldier A won't hear you grunting. When he turns around press to pull yourself back up. Count one-one-thousand before running north to the next area.
 * 3. Stalk Next to Soldier A; Hang Next to Soldier A

Los Cantos: Ridge
The first ramparts of an old fort are visible and occupied by the enemy. The road is blocked by concrete barriers and concertina wire. There is a single guard post manned by Soldier D who surveys the road east of him. To the north of him is a parked truck with its drivers patrolling nearby. One of them is armed with an LAW, which means being sighted by the enemy here would be especially deadly. The game probably expects you to move along the road on the east side of the map, but the security is too tight. Instead, you will bypass that by taking the western upper path along the ruins of the fort; the rewards for the effort are just too good.



Move to point 1 and equip the Love Box. Angle the camera such that it is looking down at you and try to make the front edge of the Love Box parallel with the edge of the ledge you're trying to climb. Once your'e satisfied with the alignment, hold down and use  to make sure the Love Box is highlighted, then press  to DROP the Love Box. Once outside the Love Box, climb it and the ledge above it into the rampart. Extract the prisoner, who is likely the first female solder you'll find in the game. Miller will voice his enthusiasm every time you extract a female prisoner of war. Move north to point 2.
 * 1. Climb Up the Rampart

Press yourself against the wall with and angle the camera such that the wall you're pressed against forms a plane. Once Soldier E crosses that plane and is completely obscured, get off the wall and make a curved approach to point 3 to ensure Soldier E doesn't perceive you.
 * 2. Wait for Soldier E

While next to the rampart, simply run off the edge at point 3. Move north to point 4, keeping the ruined walls between you and Soldier F. You want to be far away enough that when you do drop down, you won't make a loud enough noise to attract Soldier E's suspicion.
 * 3. Keep Your Distance; Drop Down

From this small wall, make sure Soldier F turns south before running past him to the northern exit.
 * 4. Observe Soldier F

Fuerte La Ladera
You now stand before the fortress. There are three soldiers on top of the wall while a single sentry is posted outside the walls. Being seen here could be deadly as there are two machineguns on the wall with soldiers right next to them. However, if you follow the instructions of this walkthrough - however counterintuitive some of them might be - you can get past them easy enough.



Get to the edge of this wall and watch Soldier G. When he turns east, it is time to move to the next area. Move to the next area. If you maintain some distance, going no further north than point 2 and staying low, the enemy will not react to you. Be quick.
 * 1. Observe Soldier G

From the low part of the southern wall of the ruined western building, press yourself to the wall with and watch him up top by holding  until he turns east and starts moving. Once he does, tilt in the direction of the wall to climb it. Do not stand upright or Soldier G will see you. Once you've hopped over the wall, move at a crouch to the ladder and immediately climb it.
 * 2. Observe Soldier I

Near the top of the ladder, angle the camera to face the northeast. Try to line yourself up with the corner at point 4. Once you're at the top of the ladder, move quickly to the corner, face the west wall and press and hold. Your camouflage will be above 70 if you do and the enemy will not be able to see you. However, you want to get as close to the corner as you can.
 * 3. Immediately Climb the Ladder



Soldier H will be facing your direction and will face the south when he turns around. He will not see you while you're pressed against the wall, so don't worry about how close you are. While you're waiting for Soldier H to turn around, Soldier I will be moving to the west endpoint of his patrol route and turn to face the south. Once he does, turn the camera to face the west and let go of.
 * 4. Wait for Soldiers H and I

Tap to stand up and gently tilt  to stalk past Soldier I and J. Continue to stalk past the corner, after which you should turn northeast toward the ladder and the hole going down to the next floor. If you messed up your timing and one of the soldiers becomes suspicious of your presence, immediately hold down to lie down; if you're far enough away from the enemy, your camouflage will be so high that they will display a ? above their head and go back to what they were doing. Keep stalking up to the edge and allow yourself to fall below. You'll land right next to the second prisoner; immediately extract him with Fulton recovery and start running to the window.
 * 5. Walk Over the Edge of the Hole

Go through the window into the gated archway. Try to dive through them by tapping while running. Otherwise, just run against the window to automatically climb them. You want to go through both, crossing the archway to the next window. The point is to use the fortress as concealment against the soldiers above, especially Soldier H. Once you're in the west wing of the fort, turn north toward the truck outside and run out the door. Run northwest along with the truck toward the tunnel entrance and the end of the level.
 * 6. Go Through the Windows

Completion
Once you enter the Crater Base, you will view an interactive graphic novel cutscene. When prompted to search the trucks, use to move a cursor, use  to zoom in,  to zoom out, and  to select a truck. You want to identify the truck with the plate 64779 and inspect it to end the mission. Checking any others will subtract from your "Cutscene Interaction Bonus" if you're going for an S-Rank. If you skip all skippable cutscenes, you will achieve an S-Rank.