Online:The Magister Makes a Move

Quick Walkthrough
#Go to Sun-in-Shadow's house.
#Investigate the clues there.
##Read ''Sun-in-Shadow's To Do List.
##Read Page from Sun-in-Shadow's Journal''.
##Talk to Florinna Avau.
#Talk to Arith Sendrul once he enters the house.
#Go to Tel Aruhn and talk to Magister Gothren.
#Steal Magister Otheri's journal from his room in Tel Naga.
#Talk to Artih Sendrul and a projection of Magister Gothren in the Council House.
#Travel to Zalkin-Sul Egg Mine and speak to Lothnarth.
#Explore the egg mine to find the Dwarven prism, while avoiding guards.
#Once you have found the prism, Lothnarth will find you. Talk to him again.
#Enter Mzanchend and find the parts required to release the prism.
#Go back to the prism and release it.
#Leave the mine.
#Return to Tel Aruhn and talk to Magister Gothren.
#Talk to Sun-in-Shadow.

Detailed Walkthrough
Sun-in-Shadow's House
thumb|left|So that's why them call them Mouths
Speak with Eoki. Eoki believes Sun-in-Shadow has lost perspective on her strategy to free the slaves. He wishes to talk with her and asks you to arrange a meeting. After speaking to Eoki head to Sun-in-Shadow's House on the southeast side of town. Upon entering, you will immediately notice the house has been ransacked, and there is no sign of Sun-in-Shadow.

Examine two journal pages in the main room and you will hear a call for help from a small alcove on the left side of the house. There, you will find Florinna Avau tied up. She explains that she was there to fit Sun-in-Shadow for a new dress when some Telvanni thugs burst in a kidnapped Sun-in-Shadow. After you untie her, Arith Sendrul will enter the house and realize that he was too late. He had come to warn Sun-in-Shadow of the imminent attack. Apparently, Magister Gothren has abducted Sun-in-Shadow in retaliation for the assassination of his previous Mouth, Ralasa Delvi. Arith, who has been promoted to his new Mouth, advises you to make for Tel Aruhn and speak directly with Magister Gothren. 

Upon entering Tel Aruhn you will notice Sun-in-Shadow locked in a slave pen. She asks you to talk to Gothren and find out what it will take to secure her release. Enter Gothren's Tower and speak with the magister. Gothren is quite displeased with the death of Ralasa, and wants you to steal the notes of Magister Otheri as recompense for your actions.

The Magister's Notes
Travel back to Sadrith Mora and enter Tel Naga. Take the lift to the Magisters' Retreat. While not considered trespassing, if you are spotted by Otheri or his apprentice, Arowende, they will teleport you back to the first floor of Tel Naga. Wait until Arowende moves to the left side of the room and the Magister is looking away from the study, and quickly sneak to study on the right side of the room. Grab the notes and head back down the lift to exit Tel Naga.

thumb|right|The Dwarven Device
Head to the Council House on the north side of Sadrith Mora and speak to Arith. After handing him Magistar Otheri's notes Magister Gothren will appear through a channeling spell from Arith. Gothren has another task for you before he will agree to release Sun-in-Shadow. Gothren wants you to retrieve the Dwarven artifact mentioned in Otheri's notes.

Zalkin-Sul Egg Mine
Head to Zalkin-Sul Egg Mine which is north-west of the Nchuleftingth Wayshrine. Outside of Zalkin-Sul you will meet Lothnarth. He warns you to avoid Otheri's guards and can answer a few questions about the mines. Head inside Zalkin-Sul. The whole mine is a restricted area, so being caught trespassing will incur a bounty. Head east and sneak past J'ghaim and enter the basket hiding spot. Wait for the sentry to reach the top of the incline and make his way back down, and for J'ghaim to walk past the basket, then exit the basket and follow the sentry. At the bottom of the incline, when the sentry takes a right turn around the pillar, take a left around the pillar and sneak past the sentry into the next room. Enter the hiding spot, being careful to avoid being spotted by Urbutha. Wait for both Foreman Naros and Urbutha to be on the right side of the hiding spot, then quickly make your way across the bridge to the south and enter the mysterious chamber. 

This area is not restricted, so you do not need to worry about incurring a bounty. Inside the chamber you will find a strange Dwemer device. Upon approaching the device, Lothnarth will enter the room. Lothnarth makes you a proposition. He has an interested party who desires information on the device. In exchange for anything you discover, he offers to provide you with a key to Mzanchend. You can agree to his terms or pay him a bribe in order to cut his benefactor out of the deal. After making your choice, Lothnarth will explain you will need to retrieve some items in order to release the crystal.

Enter Mzanchend and follow tho corridor to the north. Take a left at the end of the corridor. Grab the Dwarven Spur Gear on the table at the southern end of the room. Head through the eastern corridor until you find yourself in a rectangular room. grab the Dwarven Crank on the right side of the room and continue the path you were following. Grab the Dwarven piston on the bench towards the end of the corridor and then enter the door to Magister Otheri's Laboratory. Upon entering the main chamber, the Mzanchend Guardian will detach form the ceiling. Defeat the guardian and retrieve Dwarven Release Switch from the Dwarven coffer in the back of the room. If you agreed to Lothnarth's proposition instead of paying him, grab the technical logbook in the northeastern corner of the room. Exit through the door near the coffer. Follow the hallway to the end and exit through the door. Take a left and go back through the door to the Mysterious Chamber. Use the items on the machine's base, release the crystal and take it. Upon releasing the crystal, the mine will start to collapse, and Keesu will run into the room. He tells you the kwama have gone into a frenzy, and are attacking everyone in sight. Exit through the door on the right and follow the path through the mine to the surface.

thumb|right|"We're done here. Begone"
Head back to Tel Aruhn and give the prism to Magister Gothren. Magistar Gothren agrees to free Sun-in-Shadow, and has Volm Orenim bring her in to release her. Speak with Sun-in-Shadow, who thanks you for freeing her. She promises to lay low for a while and patch things up with Eoki. After finishing the quest she will approach the Magister and chastise him for abducting her.

:Sun-in-Shadow: "I am a free mage of House Telvanni. You had no right to imprison me!"
:Magister Gothren: "You presume to lecture me? You who conspired to kill my servant?"
:Magister Gothren: ''"Thank whatever scaly gods you worship that I didn't rend the flesh off your back and feed you to the tower's roots! Cross me again, and your life is forfeit."
:Magister Gothren: "We're done here. Begone."''

The Magister will then teleport her out of his tower.

Notes
Before Patch 3.0.8, this quest may have been impossible to complete, as Florinna Avau would sometimes not appear. (Bug confirmed on both PC and Xbox One)

Quest Stages