You get the mission "Martial Law" as a Sith Inquisitor, after completing the mission "The Secret of Tulak Hord"
Open your mission log:
Martial Law
Overseer Harkun is growing increasingly furious over your success at the trials. To remedy this, he has sent you to complete a trial of combat. You are to report to the combat training room on the second floor of the Sith Academy, and speak to the training master there.
Exit the Overseer's chambers and go up the stairs to the 2nd floor. The Training room should be on the far east of the 2nd level.
When you enter the training room, you are ambushed. Turns out this was a setup by Overseer Harkun! Wydr asks you if you remember his brother and him from downstairs with Harkun. Balek apologizes that it has to be this way. Tell them this isn't starting very well. This sounds vaguely like a threat. You ask them what you ever did to them. Balek says he liked you. But Harkum made them a deal, they kill you, they go home. Tell them this is a big mistake and that they will regret that. Balek says they don't want to do this, but they know that they cannot beat Ffon, and they will never be Sith. At least this way they can go home, alive.
Defeat Balek and Wydr. Then you need to return to Overseer Harkun in the Academy and show him just how futile his attempts to stop you are. None of the others show up, Harkun assumes they are dead. Only you and Ffon remain. Ask him where his little pet is. Overseer Harkun tells you that he sent him ahead since you took so long returning.
Your final trial will be to retrieve an ancient map from the innermost chamber of the Naga Sadow's tomb - which has never been breached in thousands of years. But before you get the map, you'll have to awaken an ancient assassin called a Dashade that sleeps in the tomb. You cannot access the map without him. The Dashade are a lost race of assassins that the ancient Sith used to devour their Force-using enemies. This one'll probably eat you the moment he's freed. You will be competing with Ffon for this map. Whoever brings it back will be Lord Zash's apprentice. The other will die. And Ffon's already started, so his advice for you is to start running.
Lord Zash suddenly shows up. Harkun asks her what she is doing here. She replies asking whether he is implying that a Lord of the Sith don't have the right to go where she pleases within the Academy of the Sith. She saw the last acolyte arrive. She wanted to see the hopefuls go on their final trial. She asks Harkun where Ffon is. He tells her that Ffon finished his trial early so he sent him on rather than keeping him waiting for you. She says that's a pity because she just finished translating the wonderful text you brought from Tulak Hord's tomb, and it's most illuminating. The map cannot be retrieved without it. Feel free to mock Harkun for this. The overseer is very upset. Lord Zash turns to you with instructions on what you must do to free the Dashade. There are rods scattered throughout the tomb of the Naga Sadow. These rods are the keys to the chamber where the ancient assassin is imprisoned. You will need to place the rods in the chamber door and electrify them. You will not be able to retrieve the map without the Dashade.
Lord Zash says she will return when both acolytes are back from the tomb, and orders Harkun not to do anything further to affect the outcome of the trial.
This ends the mission "Martial Law" and starts the next mission, "A Map for the Future".