This is the very last story quest (for now, anyway). It's very, very deep into the game.
-First you'll do the story quests up to beating Gideon at the Nightspire.
-Next you have a short quest line that leads to the estate.
-Then the next story quest is getting 100 loyalty tokens. These comes from the chests you get when you finish a prestige quest (to get prestige quests, you need to get honored reputation with a faction and be level 25). I'm unsure if you can sit on the reward chests and then open them after you start this quest, the next two steps work that way though.
-After that is 500 blood tokens, these come from the field boss chests. You can stock up on chests beforehand and open them all once you get the quest, I started with about 200. Chests opened before you get the quest don't give blood stones.
fatjay4lisa commented that you can also get them from bosses in crusades, which will give you progress toward the 50 crusades achievement as well.
-After that is 150 warrior talents (these come from dungeon chests, though I don't think all of them drop them. From what I've read only the first 3, so Infernal Kitchen, Altar of Blood and Dreamscale Ruins). Again, you won't get them until you start this quest.
-Once you've finished the 150 warrior talents, you'll be sent to the Timeless Jungle. Once you approach the quest marker there, this will unlock.