Online:Opening the Portal

Quick Walkthrough
#Speak with Tanval Indoril.
#Speak with Genvis Faledran and retrieve the Focus Stone of Fire.
#Speak with Levisii Gilvayn and retrieve the Focus Stone of Wrath.
#Speak with Mavos Siloreth and retrieve the Focus Stone of Binding.
#Place the Focus Stones and talk to Tanval.

Detailed Walkthrough
Tanval tells you that the spirits that bound Sadal in the first place are awake... and they're not very happy. You need to impress them if you want them to open a portal to Sadal's Prison so you can vanquish him again. The first spirit you're going to want to talk to is waiting on the platform in the center of the caldera. The one surrounded by the lake of lava.

Head over to the center of the caldera and talk to Arch-Mage Genvis Faledran. He tells you that three Focus Stones are required to open the way to Sadal's prison. You're going to retrieve the first one for him. The Focus Stone of Flame is located on the south side of the caldera, and you're going to have to cross a lake of lava to reach it. There's debris in the lava that you can jump on to to make it safely across the lake of fire. Once you have the Focus Stone of Flame, return to Genvis Faledran and speak with him for your next task.

Genvis tells you that there are other trials that you need to finish in order to retrieve the focus stones and prove your worth to the ancient Chimer mages. A colleague of his is the bearer of the next trial. Meet her at the top of the stairs leading into the caldera.

The next mage you'll need to impress is Levisii Gilvayn, who wants to test your patience. She teleports you to a level above for her trial. There's a focus stone in the back of the nearby cave, and she wants you to retrieve it. However, you'll need to be patient to nab it. She tells you to "follow the spells they took to contain Sadal," and she means this in a literal sense. There are images of Chimer mages from ages past. Follow the spells that they cast. Their beams of magic show you which direction to go. Straying away from the designated path will teleport you back to the entrance of the cave to try again. It's like playing "The Floor is Lava", and the only safe place is the invisible path revealed to you when the illusory mages cast their spells. It's safe to cross even when they're not casting, as long as you know which direction the mages cast in, and you follow the path. When you have the stone, talk to Levisii. Feel free to run somewhere that's off the mages' path for a free ride to the entrance of the cave.

The spirit sends you to the top level of the caldera, and who do you see but good old Mavos Siloreth. You need to retrieve the Focus Stone of Binding for him. His puzzle involves red magic. Watch where the misty red rings of magicka are. They will burst into a fountain of red magicka, which will send you back to the beginning of the puzzle when touched. Be careful, and watch where the misty rings start appearing. Watch where they spawn, and go in after the fountain they produce dissipates. When you have taken the stone from the back of the cave, feel free to touch a fountain to return to the beginning of the puzzle and talk to Mavos, who sends you all the way back down and instructs you to place all three focus stones on their proper pedestals so that the Chimer mages can open the portal to Sadal's Prison.

Return to the center of the caldera and place the Stones of Wrath, Fire and Binding. The Daedric pedestals are arranged in a triangular shape: one stone for each pedestal. Once you've placed the three Focus Stones in their places, wait for the spirits to open the way. After the portal is open, speak with Tanval Indoril to finish this quest and begin the next.
  

Quest Stages