The Enigma Order

The Cipher of Damnation is an extremely long quest line in Shadowmoon Valley. It is a prerequisite for attunement to The Eye in Tempest Keep and Mount Hyjal in Caverns of time.
"*" Indicates quests with rewards.

Quest Line
1[A] - http://www.wowhead.com/?quest=10680 - "The Hand of Gul'Dan"
1[H] - http://www.wowhead.com/?quest=10681 - "The Hand of Gul'Dan"
2 - http://www.wowhead.com/?quest=10458 - "Enraged Spirits of Fire and Earth"
3 - http://www.wowhead.com/?quest=10480 - "Enraged Spirits of Water"
4* - http://www.wowhead.com/?quest=10480 - "Enraged Spirits of Air"
5 - http://www.wowhead.com/?quest=10513 - "Oronok Torn-Heart"
6* - http://www.wowhead.com/?quest=10514 - "I Was A Lot Of Things..." - Most annoying quest ever implemented in World of Warcraft.
7 - http://www.wowhead.com/?quest=10515 - "A Lesson Learned"
8 - http://www.wowhead.com/?quest=10519 - "The Cipher of Damnation - Truth and History"

At this point, the quests diverge into three separate lines (which can be done in any order) for each of Oronok's three sons who will in turn help you obtain the three Fragments of Damnation.

Quest Line I - First Fragment of Damnation
1 - http://www.wowhead.com/?quest=10521 - "Grom'tor, Son of Oronok"
2 - http://www.wowhead.com/?quest=10522 - "The Cipher of Damnation - Grom'tor's Charge"
3* - http://www.wowhead.com/?quest=10523 - "The Cipher of Damnation - The First Fragment Recovered"

Quest Line II - Second Fragment of Damnation
1 - http://www.wowhead.com/?quest=10527 "Ar'tor, Son of Oronok"
2 - http://www.wowhead.com/?quest=10528 - "Demonic Crystal Prisons"
3 - http://www.wowhead.com/?quest=10537 - "Lohn'goron, Bow of the Torn-heart"
4 - http://www.wowhead.com/?quest=10540 - "The Cipher of Damnation - Ar'tor's Charge"
5* - http://www.wowhead.com/?quest=10541 - "The Cipher of Damnation - The Second Fragment Recovered"

Quest Line III - Third Fragment of Damnation
1 - http://www.wowhead.com/?quest=10546 "Borak, Son of Oronok"
2 - http://www.wowhead.com/?quest=10547 - "Of Thistleheads and Eggs..."
3 - http://www.wowhead.com/?quest=10550 - "The Bundle of Bloodthistle"
4 - http://www.wowhead.com/?quest=10570 - "To Catch A Thistlehead"
5 - http://www.wowhead.com/?quest=10576 - "The Shadowmoon Shuffle"
6 - http://www.wowhead.com/?quest=10577 - "What Illidan Wants, Illidan Gets..."
7 - http://www.wowhead.com/?quest=10578 - "The Cipher of Damnation - Borak's Charge"
8* - http://www.wowhead.com/?quest=10579 "The Cipher of Damnation - The Third Fragment Recovered"

After completing the quests for the three Fragments of Damnation, the lines converge and you need to kill one last boss.
Final* - http://www.wowhead.com/?quest=10588 - "The Cipher of Damnation"

Rewards:

Everyone gets http://www.wowhead.com/?item=31074 - Fire Resist Neck

Choose one of the following:
http://www.wowhead.com/?item=31036 - Caster Staff
http://www.wowhead.com/?item=31038 - Healer Staff
http://www.wowhead.com/?item=31062 - Paladin/Shaman 2H Axe
http://www.wowhead.com/?item=31071 - Tanking 1H Axe
http://www.wowhead.com/?item=31072 - Bow
http://www.wowhead.com/?item=31073 - Melee Dagger

After completing the quest, you will get a message in the mail from Khadgar. If you go to Shattrath, he will tell you to talk to A'Dal, who unlocks the the three Trials. These are prerequisites for attunement to The Eye in Tempest Keep and Mount Hyjal in Caverns of time.