Sartan is first encountered in a pit during Act I, Chapter 9 (Windstone Fortress). Speak to him and agree to talk to the Captain on his behalf after the fortress is secured to initiate the quest to free him. After activating the Azunite Artifact and having blown a hole in the north wall, which completes step 7 of the above primary chapter, return to Captain Dathry, who's standing at the end of the street just north of Sartan, to bring him the news. Speak to Soldier Orayne, who's standing behind the captain, and ask him to release Sartan to cause the platform he's standing on to be raised, releasing him from the pit. If you fail to add him to your party after freeing him from the pit, he returns to the Eirulan Inn and awaits your party's return near the bar. If you have also failed to recruit Vix, both of them will be standing near the bar. If you need to recruit him, teleport to the Town of Eirulan, then proceed north to the Inn tramway and ride it across to the Inn. Enter and speak to him and ask him to join your party. Once he's in your party, teleport to the Town of Kalrathia, then head down the stairs and again down the southeastern stairway. Proceed southeast a few steps, then turn south and enter the tavern. Speak with Feltan the Drunkard, who'll mention spies, which piques Sartan's interest. Feltan will eventually mention Osric, whom imprisoned Sartan in the pit in the Windstone Fortress and tells Sartan that he can be found in the Eastern Plain of Tears. Permit Sartan to go after him and you'll have initiated Sartan's Suspicion. Return to the Kalrathia teleporter and go to the Eastern Plain of Tears.

Head south initially toward a number of skeletons hanging from trees. Pass through them and turn east, then follow the path until it turns north. Leave the path and continue heading due east for a short ways until the encounter the entrance to A Mysterious Carven. Enter it and proceed straight back to the east toward the star on your compass. If you don't have Sartan in your party, Osric will tell them to go away, else Sartan will tell Osric, that he wants to join the resistance and Osric will open the door for him. Osric recognizes Sartan and asks for a chance to explain (that he's not a Morden spy), but Sartan refuses to listen and clobbers him, killing him on the spot. Soldier Orayne then appears and is aghast at what Sartan has done. He tells Sartan that Osric was spying for the resistance not the Morden side. Sartan becomes remorseful and volunteers to rescue the prisoners being held by the Morden in their nearby arsenal to make amends.

Exit the cavern and return west to the path, then proceed north past more skeletons until they reach The Ruins of Okaym. Continue along the path, passing east of the Eastern Plain of Tears teleporter and then past the entrance to A Large Abandoned Shelter. Proceed down the hill toward the Ruins of Okaym teleporter. Just past the teleporter, the path turns to the north. Leave the path at this point and head west toward more ruins, with skeletons suspended from broken arches, passing just north of them and they'll arrive at the entrance to A Morden Arsenal.

Enter the Morden Arsenal and battle your way through Morden enemies, while proceeding west. Jog south then continue west until the star looms large on your compass. Your party will encounter a number of soldiers imprisoned in four Morden cells. Speak to any one of them to be told to fire at the explosives in front of the four doors to free the prisoners within. Have a character with a ranged weapon, or any character who can unleash a destructive spell, fire at each of the four explosives to free all of the soldiers. When this is accomplished, you'll be told to have your party return to see Soldier Orayne. Explore any to all of the side chambers if you wish, then exit the arsenal.

Return to A Mysterious Cavern and speak with Soldier Orayne again. Soldiers Asher and Lathan are standing nearby but can not be spoken to. Sartan will report that the prisoners have been freed, and they vouch for his bravery. They decide that his guilt is punishment enough and thus ends this quest.