Metal Gear Solid: Portable Ops/The Silo

You will now need to head to the Silo.

Silo Entrance
You have 5 minutes to reach the exit, and there now are cameras that can spot you, so try to take Chaffs with you if you can.

Recruits
Now is a good time to continue the recruitment of Sokolov and to think about the recruitment of EVA.

Silo Complex
You must infiltrate the complex while avoiding the cameras (bring Chaffs) and open locked doors. The first locked door is unlocked with a key you can find on top of crates in a room nearby. The next three doors have frequencies tied to them, one is written on the wall, then one on the ceiling, and finally the last one on a window. Then, you must cross the railing and retrieve a key, there is a camera but you can easily avoid it when it's looking towards the wall. Then, drop down to the railing below. You'll then return to the map to prepare for the finale.

Silo Complex (again)
Come prepared, because there will be a Boss Fight:

After the fight there will be a cutscene and you'll return to the map.

Launch Control Room
Come prepared again, because there will be a Boss Fight:

When Gene is defeated, the game is finished.