Once you have collected all four Star Maps, you will see a new entry on the galaxy map on Ebon Hawk: Star Forge System. Please note, once you target the Star Forge system, there is no going back. If you want to go help Canderous with his duel on Tatooine, or chase down Xor for Juhani or even win the swoop races on Manaan, now is the time. Also note there will be no more merchants for the rest of the game. You will have to live on what you have and what you can find. So now might be a good time to visit Yavin Station or the premium merchant on Korriban.

When you travel to the Star Forge system, your ship will crash on the beach on this unknown world. Your mission is to disable the disruptor field that caused the crash and collect enough ship parts to repair your engines. Now you will discover the history of the Star Forge, meet the descendants of the "Builders" (you've already seen one in the computer on Kashyyyk) and the plot will diverge between light and dark (you have to finally make a meaningful choice).

Central Beach

1. Ebon Hawk has crash landed here. The first time you leave the ship, you will have to fight some Rakata warriors. After they are dead, some other aliens will appear from among the rocks and thank you for saving their lives.
2. There's some wreckage here surrounded by Rakata warriors.
3. Exit to North Beach
4. Exit to Temple Exterior

There are (sort of) two ways to handle this. If you want two different versions of Rakatan history (the superstitious version and the real version) you should first visit North Beach. If you just want the official history, head for the Temple Exterior. IMO, there's no point to getting the superstitious version of history so head straight for the temple.

Temple Exterior

This area is crawling with rancors (yes, rancors). You can probably avoid most of them by just sidling around the outside edge of the area from point A to point B. Once you come for the temple opening ritual, the rancors will be gone.

1. Exit to Central Beach
2. Exit to South Beach
3. Mandalorian camp. The Mandalorians are cloaked, but will de-cloak when you enter their camp. There's really not much point in fighting them unless you are just looking for some loot and some XP.
4. Temple entrance. You can't get inside without the help of the Elders. Once you have secured their help, return here alone for the ritual that will gain you entrance to the temple. During the ceremony, Jolee (and Juhani if she is in your group) will show up and demand to go with you. Take them or not as you please, but be aware the interior of the temple is crawling with dark Jedi, so you might want them along.

South Beach

1. Exit to Temple Exterior
2. Wrecked ship. There's a set of salvageable parts here that you will need to repair Ebon Hawk. Watch out for mines, they are extremely well hidden. Mission is a good choice if you have been maxing her Demolitions and Awareness skills (which you should have been doing). She can not only spot the mines, but recover them as well. You can then use them later. As an added benefit, by not triggering the mines you'll get enough ship parts to repair Ebon Hawk (you'll still have to defeat the One later...)
3. More rancors here. Walk through this corridor cautiously.
4. Entrance to Elder Settlement. You will be met at the entrance by a hologram that should give you permission to enter

Elder Settlement

1. Exit to South Beach. When you first come here, you will meet with the council just inside this door. They will explain what is going on and tell you their help is required to enter the temple, where the disruptor field is generated. They will only help you if you first help them by freeing one of their scouts from the compound of the One, one of the more primitive Rakata inhabiting the planet. The One's compound is on North Beach, so away you go...(You can explore the Elder Settlement first, if you wish.)
2. Researcher Ll'awa is here studying Rakatan genetics. He wants to isolate the gene that makes them force insensitive. You can agree to help him by getting genetic information from the temple.
3. Keeper of History Orsaa is here and can fill you in on the history of the Infinite Empire and the Star Forge. Nice for background information only. There's a computer in the room behind him, but it's not much more informative or helpful than Orsaa.

North Beach

1. Exit to Central Beach
2. Entrance to Rakatan Settlement

If you come here prior to visiting the Elders, the Rakata will be non-hostile and wish to take you to their leader, the One. Agree to go if you are looking for the "alternate" history of these people. Once you have made your deal with the Elders, every Rakata here (and their pet rancors) will be hostile, so power up before coming out into the open.

Rakatan Settlement

Once you've made your deal with the Elders, all the Rakata in here will be hostile.

1. Exit to North Beach
2. Rakatan Loremaster. If you come while they are non-hostile, he'll give you the alternate history of the Rakata.
3. The One. If you come here before visiting the Elders, this is where you will be brought first. The One wishes you to invade the Elder Settlement and bring him back their secrets. I don't know if this works or not, I've never tried it. If the Rakata are hostile, the One will open the four cages and release his rancors. My suggestion is to go into solo mode and then fill the eastern corridor with mines. (If you've got Mission with you and let her recover the Deadly Plasma Mines in South Beach, let her lay those. Just one of them will take down a rancor...) Then go back into party mode and enter the room to trigger the cutscene with the One. (You can go in solo, but the cutscene transports your companions in anyway.) As soon as the One opens his cages, run all your party members back through the corridor and let the One and his pets follow and get softened up by the mines.
4. Elder prisoner is in this cage. Let him go to obtain the cooperation of the Elders.
5. Ship parts are available in this cage. With these parts and the ones collected from South Beach, you have enough to repair Ebon Hawk; but, you still need to shut down the disruptor field.

Return to the Elders and arrange to meet them at the temple entrance for the ceremony. Remember to go alone.

Temple Main Floor

1. Exit to Temple Exterior
2. West guard room and exit to Temple Summit. You won't be able to open this door until you visit the catacombs
3. There's a computer console in this room that you can use to wreak havoc, including opening the Armory.
4. Prototype droid command room. The computer in here gives you additional options for dealing with the droids in the East Guard Room.
5. East guard room and exit to Temple Catacombs.
6. Armory. In addition to a lot of loot, there's a workbench here to upgrade your saber with some of the new crystals you've found. In the room right before this is a powerful dark Jedi, so power up before approaching.

Temple Catacombs

1. Exit to main floor
2. You have to walk this set of floor tiles in an H pattern in order to unseal the door:
   
   
   
   In order walk 1-2-3-4-3-5-6-7-6-8
3. Rakatan computer. You can get more info on the Rakatan, but your primary purpose is to have the computer unlock the door to the summit. Don't forget to request genetics data if you are helping the Elder researcher.

Temple Summit

1. Exit to main floor
2. Bastila waits for you here. She has turned to the dark side and will attack immediately. Beat her down a bit and she will admit you are stronger. Now is when you have to make your choice:
   1. Light Side: try to turn Bastila, she will refuse and escape back to the Star Forge in her ship. Shut down the disruptor field and the temple energy shields at the nearby computer. Return to Ebon Hawk, explain about Bastila and enter the ship. Head back to the engine room and "use" the engines to repair them. Now go to your Galaxy Map and target Star Forge (not Star Forge System).
   2. Dark Side: declare yourself the new Lord of the Sith and demand Bastila's alliegance. She will join with you and you will then have to kill Jolee and Juhani. Shut down the disruptor field and temple energy shields. You and Bastila will return to Ebon Hawk where you will proclaim your new title to your group. Carth, at the least, will oppose you and run away. (If you are female and romanced him, you will see him again.) Canderous, HK-47 and T3-M4 will continue to support you. Mission will oppose you, but Zaalbar wants to honor his life debt. If you have Affect/Dominate Mind, you can Force Persuade Zaalbar to kill Mission (a truly evil thing to do). Otherwise, Mission forces you to kill her and Zaalbar will defend her so you have to kill him also.