You get your final trial in the Sith Academy, "A Map for the Future", after completing the mission "Martial Law".
Open your mission log:
A Map for the Future
You have been given your final trial. You must venture into the tomb of Naga Sadow and retrieve an ancient map for Lord Zash. Unfortunately, to get to the map, you have to awaken an ancient creature known as the Dashade. To access the Dashade's chamber, you must first gather the ancient rods hidden throughout the tomb. Gather the ancient rods from within the tomb of Naga Sadow.
Tasks:
Collect the Rod of Hast
Collect the Rod of Fury
Collect the Rod of Wrath
Collect the Rod of Despair
Exit the Sith Academy. Follow the road to the NE to reach the tom of Naga Sadow. Open your map and locate the four rods, then collect each of them. The tomb of Naga Sadow is full of rival acolytes, all hunting for the same ancient map. Erase the competition and defeat 12 rival acolytes to complete a bonus mission, "Crush Your Rivals". Once you have gathered all the rods, you need to place them at their altars inside Dashade's Chamber. While doing this, destroy 10 Ancient Droids for the bonus quest "Naga's Sadow's Wardens". In the chamber, place all of the four rods on the Altars. Then meditate at the Altar. Enter the Dashade's Chamber. It appears that Dashade is not merely asleep here, but imprisoned. Talk to Khem Val. He is the servant of Tulak Hord, who was called Lord of Hate, Master of the Gathering Darkness, Dark Lord of the Sith. Together, Tulak Hold and him devoured their enemies at the battles of Yn and Chabosh and brought the entire Dromund system to its knees. He now awaits Tulak Hord's return. You tell him Tulak Hord is dead.
Khem Val the Dashade devours Force users. After being imprisoned for centuries, he is very hungry. Your task is to defeat him inside the tom of Naga Sadow and force him to help you find the ancient map. Once you defeat Khem Val, tell him to Obey or Perish. He will join you as your companion. Your task now is to find a way through the Debris Wall. With Khem Val now in your service, you should be able to clear the Debris Wall blocking the way to the innermost chambers of the Tomb of Naga Shadow. Interact with the Debris Wall, and Khem Val will break it. You now need to find and retrieve the ancient map in the tomb of Naga Sadow.
As a bonus, you can slay the Terentatek Mauler for the mission "The Final Obstacle". This is a level 10 boss so the battle will be quite challenging, even with the help of your companion. Then interact with Naga Sadow's ancient map. Once you have the Ancient Map, return to the Sith Academy to report your success to Overseer Harkun (you should Quick Travel if possible).
Back at the Sith Academy, Ffon tells Harkum that he could not get to the map. He went into the tomb, saw the Dashade across the chasm, but could not get to it. Interrupt them and tell them you got the map. Ffon thinks you cheated, he does not understand how you released the monster. Khem Val says he is not a monster, he is a servant of Tulak Hord, devourer of the rebels at Yn and Chabosh, consumer of the Dromund system, and he is hungry. Harkun snatches the map from your hand, and wants Ffon to deliver it to Lord Zash. You can order the Dashade to kill them both, but Lord Zash steps in telling you to keep your pet at bay. She asks Ffon for the map. She asks him if he was the one who found it for her. She threatens him that he wouldn't dare lie to her, because it would be a shame for her to discover that he lied. She asks him once again if he brought this map back from Naga Sadow's tomb. After some hesitation, he finally admits that he did not. Lord Zash then kills Ffon, and refers to you as her apprentice. She tells you to meet her at her chambers upstairs.
After Lord Zash leaves, Overseer Harkun tells you that this is not the end, without Lord Zash to save you, you're nothing. He has connections that will hunt you wherever you go. You can tell him to Deal with it (DARK), or that he was a good teacher (LIGHT) or to talk all he wants (DARK). If you tell him that he was a good teacher, he is surprised and flattered, and says it's an overseer's job to inspire his charges.
Your task now is to report to Lord Zash in her chambers on the second floor of the Academy. Climb up to the 2nd floor, her chambers are to the Southwest. She congratulates you on becoming her new apprentice. Tell her you are grateful. She says there is a lot of work ahead of you. She wants you to meet her on Dromun Kaas. There you can talk more. That is where the map leads. Plus, the capital of the Sith Empire is a good place for an apprentice to start. She will meet you in her chambers in the Citadel in Kaas City. There you can speak more freely of the work ahead, without the fear of unfriendly ears. She gives you the lightsaber she had as an apprentice, she wants you to have it.
As you leave her office, you meet with Apprentice Ortosin and some thugs. He tells you that Darth Skotia has a message for you. He does not want you to go to Dromund Kaas. They attack you. Accept your reward and equip your new lightsaber before defeating them.
This ends the quest "A Map for the Future" and starts the quest "Go to Dromund Kaas".