The Dwarven Dream

All of the archaeology rare artifacts dealing with Demonic fragments involve finding pieces of a Titan disk for Brann Bronzebeard. There are five of these artifacts: [item=131724], [item=131735], [item=136922], [item=131743], and [item=131732].

Once you have acquired all five of these artifacts, Brann will have a followup quest: The Relic Renewed. Completing that quest, which involves nothing more than waiting a few moments for Brann to assemble the pieces of the disk you have recovered, will reward you with ten of each Legion keystone item (Mark of the Deceiver, Ancient Suramar Scroll, and Highmountain Ritual-Stone) and this achievement.

Apparently, every Brann-related archaeology chain in Legion also has a hidden tracking quest that is probably related to this achievement. These quests have completed for me together with last quest in the corresponding chain:
[quest=41867] with Corrupted Studies
[quest=41868] with The Gates of Valor
[quest=41869] with The Apocalypse Bringer
[quest=41870] with Dark Secrets
[quest=41871] with Darkheart Thicket: Through the Fog

So this means you can check which requirement you are missing with the usual IsQuestFlaggedCompleted macro. In particular,
/run for i=0,4 do print("Week "..i.." : "..((IsQuestFlaggedCompleted(41867+i) and "Yes") or "No")) end

You cannot use original non-hidden quests, because they immediately reset after their two weeks; but hidden trackers do not.

Once I completed last quest of Mac'Aree chain and thus (hiddenly) last tracker, Brann offered The Relic Renewed, "The Relic Renewed", that is not in the database as I am writing this. This quest rewarded 10 of each of three Legion archeology keystones and also this achievement.

Spoiler

When I completed this quest, Brann mentioned there is still a missing piece - hole in the disc. However, Wowhead currently only lists five Brann tracking quests, so apparently this is all content currently in-game. Probably this is reserved for future patches - we are coming to the end of archaeology chains, but Legion will probably go for more than a year further. So maybe Blizzard are planning to add some more archaeology chains and rares in one of the future patches and then we will also complete the disc.

These parameters were changed in 9.0. The script should now be this--: /run for i=0,4 do print("Week "..(i+1).." : "..((C_QuestLog.IsQuestFlaggedCompleted(41867+i) and "Yes") or "No")) end