Solid Sun — South America

The Act opens in a small farming village crawling with both PMCs and Militia — from here on, lean on the map more than you did in Act 1. Climb onto the hut's roof near the start for an easy angle on the PMCs below. The barn further in holds Pentazemin and spare ammo; the door Vamp is first seen leaving hides an extra iPod track. Use the barn's ladder to get back to ground level, then move northeast toward the exit using night vision to spot the glowing footprints marking the correct path up the hillside. A codec call partway up introduces Campbell's wife and the Psyche meter beneath your health gauge.

Follow the Militia around the first corner, but hold back — a sniper starts picking them off, and Otacon will call it out. Hug the wall to the right, climb the low ledges, and take the back route instead of the open path. Fire on PMCs from as far away as you can manage; there's little cover along this stretch, so retreat down the path if you're spotted rather than trading shots in the open.

Past the rocks, the power station comes into view below. Don't approach it head-on — swing right between a pair of tall fences, where their bases offer solid cover, and team up with the Militia already fighting there. Once a Militia soldier follows you inside to rig the station for demolition, your job here is done; when it goes up, continue northwest to meet Drebin for the second time, then head north.

Head west past the small gardens and ponds, thinning out the isolated PMCs along the main road. Use night vision to spot a pair of guards patrolling near a hut further west and take them down before continuing past a large fallen log. Hold near the log when the Militia's assault reaches this area — a squad will move in behind you and start engaging the PMCs ahead, so join the firefight from cover rather than pushing out alone.

A PMC tank rolls up to the intersection beyond the log; an RPG round ends it quickly. From the tank's position, clear the PMCs guarding the parked vehicles near the watchtower, then either loop around them or slip through the gap in the north wall beside the tower. A couple of guards remain near the exit — deal with them and continue on to Vista Mansion.

You can join the Militia's assault on the front gate directly, or swing east along a long ditch to flank around to the back of the property, where the Militia is bringing up a bulldozer to breach the gate. Cover the bulldozer and the Militia as they push in rather than trying to clear the area solo — once the gate is down, follow them into the courtyard.

Enter the mansion through a side window near the fountain rather than the front door. Inside, find the staircase and fight your way past the PMCs coming down it. Upstairs, loop through the rooms to reach a rooftop walkway, cross it, and drop back inside through an open window on the far side. Continue down through a service tunnel and up a final flight of stairs into the research lab.

A long cutscene follows: Snake reunites with Naomi, who is captured by the PMCs shortly after. Left behind, Snake has to deal with FROG soldiers patrolling the corridors in pairs — match their patrol pattern and take them down at first sight rather than letting them regroup.

Once her health drops low enough, a cutscene shows her forced back into human form. In the second phase, she slowly approaches Snake — hit her with the tranquilizer gun and back away each time she closes the distance, repeating until she's down. Finishing her non-lethally like this is required for the Solar Gun secret (see the Secrets page).

A codec call from Raiden points you toward Naomi's trail. With the path splitting often, lean on the map and keep night vision on to spot footprints and distant PMCs. A hidden guard waits inside a small hut to the north — clear it carefully, and check the surrounding area for extra items. You're on the right track once you reach a wide stream to the east of the hut; cross it and head left.

Continue east and then south to a tunnel entrance. Snake finds Naomi with Vamp waiting for him inside, leading into a vehicle battle.

Snake mans the turret on Drebin's truck through a running battle across four areas.

• Vista Mansion: Fire on anything that moves; once the truck stops, soldiers try to climb aboard — melee them off or shoot them at close range.
• The Prison: Gekko join the fight here. Shoot their legs first, then their torsos, and keep them away from the truck.
• The Power Plant: A PMC tank and a barred metal gate both block the road. Shoot the gate while the truck is stopped in front of it, then switch to the tank's turret once the truck moves — focus fire brings it down fast.
• Forest Road: More Gekko, plus a second tank that goes down even faster than the first once you're locked onto its turret. One more Gekko-heavy stretch follows before you reach the Marketplace.

Push down the market street, staying clear of Gekko legs and grabbing food supplies as stalls collapse around you. At the end of the street, a Gekko drops in front of you — don't charge it. Equip a submachine gun and focus fire on one of its legs until it goes down. Past it, you reach your destination and close out Act 2.