It is unclear whether or not you have to have the Keep of Immortality Key in inventory to get this quest. (wearing not required)(I was just offered the quest, after previously transmuting the key, so it is not required to get the quest)
It is unclear whether or not Freeportians can get this quest. (As of 2.16.15 - With the Key in my inventory I was offered the quest as a Freeport citizen).
Venture to the Ruins of Varsoon to kill the the two tomes: