The entrance from the Upper City is at the south end of the Sith base. You can return there if you need to transit back outside your hideout or change your party selection.
Reception
When you enter, you're immediately challenged by a receptionist standing behind the reception terminal in the middle of the reception area, which has a standard door in its north and west wall.
They will throw their Frag Grenade if they can do so without damaging themselves, while in melee combat they use a Stun Baton with On Hit:Stun 25% chance, 6 seconds, DC 10.
Select the Datapad in the Equip menu to read the following:
This seems to be an activity log for the day. Of interest is the following entry
"The power conduit we installed in the elevator seems to have solved the shield outage problem on the droid. Finish tuning it today."
Reception Terminal
Once the receptionist is gone, you can use the reception terminal in the middle of the reception area. T3-M4 is likely to have the highest Computer Use rank, so using him can significantly reduce the number of Computer Spikes needed.
Accessing security cameras will reveal points of interest on the map so uploading area schematics is unnecessary, and the sight of the elevator being guarded by an assault droid and two blaster turrets should indicate its importance.
Disabling the assault droid's shield is unnecessary unless you insist on using energy weapons. Opening the elevator is also unnecessary since you can get a passcard from the footlocker against the south wall of the barracks to the north of the elevator. Overloading the power conduit by its east wall will kill the three Sith troopers inside.
Taking turrets and sentry droids offline makes it possible to get to the elevator without having to fight anything but the assault droid guarding it. However, this deprives you of experience received for killing them, so hacking sentry droid target filtering is a better option: they will turn on each other, and other enemies within the Sith Base, reducing the numbers you have to fight while receiving experience for any kills (although this won't be displayed in Feedback).
As ever, overloading the terminal is not recommended, as it results in 1,000 electrical damage to everyone in the vicinity.
Cells
Beyond the standard door in the north wall of the reception area is a corridor with medical bay behind
a door in the west wall and a security terminal behind one in the east wall. If you hacked sentry droid target filtering at the reception terminal, you'll hear blaster fire as you travel through the base.
Behind the door at the north end of the corridor are the cells, which are guarded by two sentry droids. You won't have to fight either of them if you've taken them offline, and you may only have to fight one damaged droid if you hacked sentry droid target filtering.
Beyond a standard door in the east wall is a corridor guarded by another sentry droid leading to the elevator. Beyond one in the west wall is a corridor leading to the armory, beyond that in the northwest wall is a corridor leading to the control center, and beyond that in the north wall is an alcove containing a footlocker with random contents.
Otherwise, there are five wall panels on the south wall to the right of the entrance, opposite which are four cells lined against the northeast wall, the second from the right of which contains a familiar Duros who needs your help again:
You can leave the Duros where he is, release him or execute him:
Release
1
↓
2
↓
3
↓
Released
Execute
1
↓
2
↓
3
↓
Executed
Duros: Thank you, human. I do not know what you are doing inside this military base, but I am grateful. Once again I owe you a debt I can never repay. Now I must leave this place before the Sith discover I have escaped. If you are wise, you will do the same. If the Sith capture you I doubt anyone else will come by to set you free.
Light Side Points Gained: +2
Engaged cell's termination program to execute Duros
Dark Side Points Gained: -2
Barracks (Secondary)
The corridor beyond the standard door in the east wall of the cells turns south, and is guarded by a sentry droid. If you haven't used the reception terminal to take it offline, you may have to kill it.
The corridor ends at a standard door at its south end, beyond which is the elevator. There's also a standard door in its west wall, beyond which is a secondary barracks occupied by three Sith troopers. If you haven't overloaded the power conduit by the east wall in the southeast corner, when you enter you may have to kill them.
This passcard will allow you to use the elevator if you haven't already opened it using the reception terminal.
Elevator
The corridor to the east of the cells ends in a standard door at its south end, beyond which is the elevator. As you enter, a short scene plays in which the assault droid guarding it reacts to your presence, and the door to the cells at the west end of the corridor closes and locks behind you. It remains locked until the assault droid has been killed.
There are also two blaster turrets flanking the elevator in the south wall. If they haven't been taken offline using the reception terminal, they also attack. They aren't particularly dangerous in themselves, but the combination of damage from the assault droid and their supporting fire can be significant.
The two blaster turrets in the armory are identical.
You can simply run past the assault droid and take the elevator if it was opened using the reception terminal or you have the passcard from the footlocker in the barracks outside, but you cannot leave the base until it's been killed and it will be waiting for you on your return.
The assault droid is a melee attacker, so you can run back down the corridor out of range of the blaster turrets and it will follow you. If its shield hasn't been disabled using the reception terminal then it can absorb 300 points of energy and ion damage, so attacking with melee weapons or other types of damage is really recommended.
There's a transformer in the northeast corner but, despite the apparent hint given by the datapad found on the technician remains in the reception area, there doesn't appear to be anything you can do with it.
Take the elevator and prepare to face the Sith governor of Taris...
Sith Governor
The elevator takes you to the south end of a short corridor. Beyond the standard door at its north end is the Sith governor, the first Force user encountered in the game. If you're playing without a party, you may want to set some mines in the middle of this corridor so that you can lure him back to them after opening the door.
He uses his Energy Shield before he attacks. He has enough Force points to use Stasis or Drain Life five times. Stasis paralyzes for 12 seconds or 4 combat rounds while Drain Life drains 10-40 life unless the target makes a successful Fortitude save or is a droid like T3-M4.
Since he's a melee attacker using an Energy Shield (although a single use of a Shield Disruptor will be more than enough to remove it), attacking him with melee attackers of your own is advisable; so is debilitating him, although a Concussion Grenade, Minor Flash Mine or Stun Ray only have 25% chance to stun him for 9 seconds or 3 combat rounds.
You can now bring back the departure codes to Canderous Ordo in Javyar's cantina in the Lower City, but it's worth exploring the rest of the base to receive more experience and items, particularly from the armory (in fact, it might even be advisable to visit it before facing the Sith governor).
Medical
Beyond the standard door in the west wall of the corridor to the north of reception is the medical bay, occupied by a medical droid and two sentry droids, one in the southwest corner opposite the door and the other to the north by the east wall... although if the reception terminal was used to take the sentry droids offline or hack their target filtering, you may face fewer damaged droids or the medical droid alone.
Beyond the standard door in the east wall of the corridor to the north of reception is a security terminal in the central alcove of the east wall, guarded by a mine and flanked by a sentry droid on each side.
If the reception terminal was used to take the sentry droids offline or hack their target filtering, you may only face the mine, or one or two damaged droids.
Beyond the standard door in the west wall of the cells is a corridor turning south, guarded by a sentry droid. If you haven't used the reception terminal to take it offline, you may have to kill it.
There's a standard door to the control center in the west wall, and just beyond it in the east wall is another to then main barracks, occupied by two Sith troopers and two sentry droids flanking the door, and a Sith captain in the northeast corner... although if the reception terminal was used to take the sentry droids offline or hack their target filtering, you may face fewer or damaged enemies.
Remembering that each Sith trooper has a Frag Grenade and the Sith captain has threePlasma Grenades, running towards them to engage in melee combat, or away from them until they've used all their grenades, is advisable. Since they all prefer to attack from range, the walls to either side of the door can be used to block line of sight and face fewer enemies at a time.
There's also a footlocker by south wall with random contents.
Armory
At the south end of the corridor to the west of the cells, beyond the standard doors to the control center to the west and the main barracks to the east, is a locked door.
It's also guarded by two blaster turrets like those guarding the elevator, which will attack if they haven't been taken offline using the reception terminal.
The droid is more useful as a distraction than a combatant. Engage its patrol mode and it will walk to the southwest end of the corridor and open the standard door to the control center beyond. The door is mined:
The control center is split into three sections by two floor-to-ceiling computer banks, between which are two security terminals guarded by three technicians and two Sith troopers. One of these technicians is the same as the one at the north end, the other two are not:
Although they prefer to attack from range (remember each of the Sith troopers has a Frag Grenade) and the computer banks can block line of sight, some of them may notice any entry from the northeast, and the mine inside the door interferes with targeting them until it's triggered or walked around (disabling or recovering it aren't really an option unless you enter using Stealth and remain undetected). In melee combat all use a Stun Baton with On Hit:Stun 25% chance, 6 seconds, DC 10.
All will also notice an entry through the standard door in the east wall from the west corridor between the cells and the armory, which is also mined:
Although this is a better position for using a grenade (one thrown at the central Sith trooper will affect all five targets between the computer banks, always killing all three technicians), the mine causes similar targeting difficulties.