An Artifact From the Past

This is a quest involved in the Black Temple Attunement Chain:

The Black Temple attunement starts at The Altar of the Sha'tar for Aldors, and the Sanctum of the Sun for Scryers. Both are in Shadowmoon Valley.

Aldors start attunement from Anchorite Ceyla (http://www.wowhead.com/?npc=21402) at the Altar of Sha'tar in Shadowmoon Valley:
1. [A] http://www.wowhead.com/?quest=10568 [70] Tablets of Baa'ri
2. [A] http://www.wowhead.com/?quest=10571 [70] Oronu the Elder
3. [A] http://www.wowhead.com/?quest=10574 [70] The Ashtongue Corruptors
4. [A] http://www.wowhead.com/?quest=10575 [70] The Warden's Cage

Scyers start attunement from Arcanist Thelis (http://www.wowhead.com/?npc=21955) at the Sanctum of Stars:
1. [Sc] http://www.wowhead.com/?quest=10683 [70] Tablets of Baa'ri
2. [Sc] http://www.wowhead.com/?quest=10684 [70] Oronu the Elder
3. [Sc] http://www.wowhead.com/?quest=10685 [70] The Ashtongue Corruptors
4. [Sc] http://www.wowhead.com/?quest=10686 [70] The Warden's Cage

After that, the chain comes together for Aldor and Scryer.

5. http://www.wowhead.com/?quest=10622 [70] Proof of Allegiance
6. http://www.wowhead.com/?quest=10628 [70] Akama
7. http://www.wowhead.com/?quest=10705 [70] Seer Udalo

Seer Udalo is found in the Arcatraz (http://www.wowhead.com/?zone=3846) just before the last boss.

8. http://www.wowhead.com/?quest=10706 [70] A Mysterious Portent
9. http://www.wowhead.com/?quest=10707 [70] The Ata'mal Terrace
10. http://www.wowhead.com/?quest=10708 [70] Akama's Promise

After you finish this chain, you get to pick from some rewards and the chain seems like it ends. It continues however, inside Serpentshrine Cavern (http://www.wowhead.com/?zone=3607) from an NPC called Seer Olum (http://www.wowhead.com/?npc=22820) who you can speak with after killing Fathom-Lord Karathress. He starts the next part of the Black Temple Chain by offering the quest:

1. http://www.wowhead.com/?quest=10944 [70] The Secret Compromised
For this quest you just return to Akama.
2. http://www.wowhead.com/?quest=10946 [70] Ruse of the Ashtongue
In this quest, you must use the costume Akama provides, and kill A'lar in Tempest Keep: The Eye while wearing the Ashtongue Cowl. Attunement for The Eye is a whole different chain.
3. http://www.wowhead.com/?quest=10947 [70] An Artifact From the Past
In this, you need to gain access to The Battle of Mount Hyjal in Caverns of Time, and slay the first boss, Rage Winterchill. Attunement for this involves killing Lady Vashj and Kael'Thas Sunstrider.
4. http://www.wowhead.com/?quest=10948 [70] The Hostage Soul
For this you must speak with A'dal in Shattrath city.
5. http://www.wowhead.com/?quest=10949 [70] Entry into the Black Temple
For this, just speak with the naaru Xi'ri in front of Black Temple.
6. http://www.wowhead.com/?quest=10985 [70] A Distraction for Akama
Unknown what this quest asks of you, most likely you need to defend Xi'ri and make your way into Black Temple. At the end, you become attuned to enter and are granted The Medallion of Karabor (http://www.wowhead.com/?item=32649)

At this point, you are attuned and can enter Black Temple, although the chain continues and you can soon upgrade your medallion. It continues with:

1. http://www.wowhead.com/?quest=10958 [70] Seek Out the Ashtongue
You just need to find Seer Kanai (http://www.wowhead.com/?npc=23158) inside Black Temple.
2. http://www.wowhead.com/?quest=10957 [70] Redemption of the Ashtongue
This involves entering Black Temple, and killing the boss the Shade of Akama (http://www.wowhead.com/?npc=22841).
3. http://www.wowhead.com/?quest=10959 [70] The Fall of the Betrayer
After killing the Shade of Akama and returning to Seer Kanai, he asks one last thing of you. Kill Illidan The Betrayer. After doing so, you are granted the Blessed Medallion of Karabor, an upgraded version of your original medallion, and allows teleportation to the Black Temple.

As known on the quest text, it drops from Rage Winterchill: http://www.wowhead.com/?npc=17767#z0z

Aldor Video Guide: http://www.youtube.com/watch?v=bQy6VAyViEU ¹
Scryer Video Guide: https://www.youtube.com/watch?v=axqaQWiLnAI ¹

¹The quest IDs are the same for [faction=932] and [faction=934]; however, the separate videos will direct you to the applicable flight locations.

1. An Artifact From the Past
• Accept the quest An Artifact From the Past from [npc=21700], at coords 58.1, 48.2, in Warden's Cage, Shadowmoon Valley (Outland).
• Travel to Dalaran, either via one of the Dalaran teleport rings, or by using your [item=6948], and clicking the Dalaran (Northrend) portal.
• Travel to a building, in Dalaran, whose entrance is located at 32.0, 48.6. Go up the stairs and to your left there is a portal labeled: 'Dalaran Portal to Caverns of Time.' Click this Portal to be transported.
• At the [zone=2300], head into the tunnel in front of you, underground to coords 48.3, 24.5 and enter the raid instance: [zone=3606].
• Enter the instance portal located to your left, which is not gated (see video).
• Speak with [npc=17772] and select, "My companions and I are with you, Lady Proudmore." Starting this will activate the first waves of mobs to spew forth.
• Head southwest and wait for the mobs to reach you. Don't allow any of the 10 waves of mobs to pass you and enter the Alliance Base.
• After defeating the 10 waves of trash, [npc=17767] will approach. Defeat [npc=17767] and loot the [item=32459], from the corpse.
• Unfortunately, you can't run out of the instance. You will need to use one of your pieces of teleport gear or a [item=6948] to reach the [zone=6142] / [zone=6141].
• Go to the city's portal room.
- - Alliance players: go to the room above the opposite of the Innkeeper and click the Shattrath portal at coords 69, 52.
- - Horde players: go to the room above the Innkeeper and click the Shattrath portal at coords 64, 58.
• Once you have arrived on the other side of the portal, fly to and interact with the gryphon flight master, [npc=18940], at coords 63.8, 41.6.
- - Aldor players will fly to the Altar of Sha'tar, in Shadowmoon Valley.
- - Scryer players will fly to the Sanctum of the Stars, in Shadowmoon Valley.
• Fly to the Warden's Cage at coordinates 57.2, 49.6.
• Enter the Warden's Cage, and follow the underground passage and swim to [npc=21700] at coords 58.1, 48.2

Full Guide to obtain [item=32757].

If you're unsure about which stage of the quest line you are in to obtain the [item=32757], enter the following script into the chat box (special thanks to Vlad for the script):

[faction=932]

/run local y={568,571,574,575,622,628,705,706,707,708,944,946,947,948,949,985,958,957,959}print"The Aldor:"for i,q in ipairs(y)do q="10"..q print(i,"\124cffffff00\124Hquest:"..q.."\124h["..q.."]\124h\124r",IsQuestFlaggedCompleted(q)and YES or NO)end

[faction=934]

/run local y={683,684,685,686,622,628,705,706,707,708,944,946,947,948,949,985,958,957,959}print"The Scryers:"for i,q in ipairs(y)do q="10"..q print(i,"\124cffffff00\124Hquest:"..q.."\124h["..q.."]\124h\124r",IsQuestFlaggedCompleted(q)and YES or NO)end