Evil Ring quest? (spoiler?)

I read an earlier post here stating that the key to High Garendall is at the 3rd lvl of the learning tree. Where can I trigger this Evil Ring quest? I don't have the Tome of Elixers quest either.

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I think you need at least the Milla'Kara shield, and maybe the Tome of Elixers quest. Then Emilius will weaken and ask you to go get the Evil Ring to bolster his power so he can open the 3rd level.

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