Most of the activities associated with this secondary quest occur as part of the primary quest during Act I's Chapter 9 (Windstone Fortress). Shortly after your characters enter the area, where Captain Dathry and his meager band are congregated, they encounter Sartan in a square pit near Squadron Leader Taarth at the north end of the street, which runs down to a blocked fortress entrance. Speak to Sartan in the pit to learn that Captain Dathry and his men believe him to be maddened by the plague and therefore too dangerous to be running around by himself. He's obviously not and none too happy to be so imprisoned. Promise to try to help get him out to initiate the quest.

Speak to Captain Dathry to obtain the Outer Vault Key. Head down the stairway to the east, which is just south of Squadron Leader Taarth and zero to three of his rescued soldiers, depending on where you are with the The Missing Squadron! secondary quest and proceed down the corridor into the Windstone Fortress Outer Vault. Left click on the triangularly shaped Arsenal Entrance Lock on the east wall to use the Outer Vault Key and gain further access into the Outer Vault.

Continue eastward down the corridor until turning north at the statue. Open the door beyond and head into the next room and handle the Plagued Windstone Fortress Soldiers, who rush to attack. Note the pulsating yellow eye like symbol on the floor in front of the door to the east and the yellow sight hexahedron socket just to the north of the symbol. Continue north a few steps and you'll see a pile of three yellow sight hexahedron blocks on the floor next to a smaller version of the pulsating yellow eye like symbol. Left click on the pile to pick one up, then return southeast a few steps and left click on the yellow sight hexahedron socket to place a yellow sight block upon it and lower the door to the east into the floor.

Proceed east into the "Green" room, which has a slowly pulsating green tree symbol on the floor, green life hexahedron sockets to either side, with openable doors beyond them to the north and south, and a green colored door to the east. There's a chest with some gold in it to the north and a couple of Plagued Windstone soldiers or archers to deal with, but nothing else. Head through the south door to find an Urn and a couple more Plagued Windstone soldiers or archers, but more importantly a smaller version of the pulsating green tree symbol on the floor and next to that a pile of three green life hexahedron blocks. Left click on the pile twice to pick up two. Then return to the previous room and place a green life hexahedron block in each of the two green life hexahedron sockets to lower the door to the east.

Continue east into the "Red" room, which has a slowly pulsating red symbol, which doesn't look like anything familiar, on the floor, red blindness hexahedron sockets to either side, and a red colored door to the east. Several Plagued Windstone Fortress Soldiers and Lieutenant Namyek inhabit the north side of the area, and must be dealt with. Once Lieutenant Namyek has been dispatched, you receive the Inner Vault Key.

Proceed into the Inner Vault area. Over on the south side of the area, you'll see a pile of three red blindness hexahedron blocks behind a smaller version of the slowly pulsating red symbol in front of the door to the east. Left click on the pile twice to pick up two of the blocks, loot the three nearby urns for some gold, then return north toward the pulsating red symbol. Left click on each red blindness hexahedron socket to place a red blindness hexahedron block in each, which lowers the door to the east, and out generally comes one Plagued Windstone Fortress Soldier. Continue into the small room to the east and left click on the triangular symbol on the east wall to use the Inner Vault Key and gain access to the Inner Vault.

Enter the Vault and head on in to meet a mob of Plagued Windstone Fortress Soldiers plus the Plagued Windstone Fortress Grand Wizard, around the corner to the south. Battle them to extinction and once accomplished, you'll note a slowly pulsing star to the south on your small compass map and a pile of purple death hexahedron blocks to the west at the back of the room. Head north and loot the bookcase, then west and grab four purple death hexahedron blocks.

Now head west to the Font of Azunite (blue) Fire. Left click on it to activate the Azunite Artifact (bowl), they received in the Azunite Cavern awhile back. There's a lot off loot to be had in this room, so take the time to retrieve it before heading through the door to the northeast. Here's where the Dusty Key, received for completing the The Missing Squadron! secondary quest is used. Use it and the door drops, revealing four purple death hexahedron sockets in the room beyond.

Enter the "Purple" room and place the four previously gathered purple death hexahedron blocks in the four purple death hexahedron sockets to lower a door to the west, revealing two treasure rooms beyond, the latter one holding a Big Chest. Loot the area, then return to the main room and proceed back out onto the main street of Windstone Fortress.

Head a few steps north and speak to Captain Dathry, who's standing at the end of the street just north of Sartan, to bring him the news. The captain will then order his men to go get and place explosives to clear the rocks, which a Dark Wizard caused to fall, blocking their progress. Then 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.