Twilight Highlands quests

Twilight Highlands is the fifth and final level-up zone of World of Warcraft: Cataclysm, found on the east coast of Khaz Modan on the Eastern Kingdoms. The quest chain starts in either Stormwind or Orgrimmar and involves a short chain in the capital city before heading out to the highlands proper.

The first half of the zone plays out in separate storylines for the Alliance and Horde, but once players reach the Maw of Madness, they share the storyline for the rest of the zone.

The progression of the storyline is tracked in the achievement Fading into Twilight

The Alliance-only portion of the Twilight Highlands storyline starts with a quest chain in Stormwind City, before reaching Highbank in the Highlands proper.

To Highbank.

After the second Twilight Shores:

To Firebeard's Patrol.

After The Way is Open:

After Dropping the Hammer, two quest chain forks open up, starting with Dunwalds Don't Die and A Coward's Due:

After Dropping the Hammer:

After Dropping the Hammer:

Upon completion of the Dunwald and Thundermar forks:

The Horde-only portion of the Twilight Highland storyline starts with a quest chain in Orgrimmar before reaching Dragonmaw Port in the Highlands proper.

To Dragonmaw Port

After Returns to the Highlands, two quest chain forks open up, starting with The Southern Flank leading to The Krazzworks and The Northern Flank leading to Bloodgulch:

After the Alliance/Horde-only portions of the storyline, players from both sides wind up at the Maw of Madness and generally share the storyline for the remainder of the zone.

After Wild, Wild, Wildhammer Wedding for the Alliance or after dealing with the ogres and cultists at Glopgut's Hollow and The Twilight Breach for the Horde, it is revealed that the Twilight's Hammer have summoned Iso'rath, a servant of the Old Gods who is tormenting anyone who gets near it with nightmares. The Earthen Ring is trying to destroy its brain and has asked for the help of adventurers.

Completing this part of the storyline awards the achievement Consumed by Nightmare.

To the Vermillion Redoubt:

After surviving the Maw of Madness, the adventurer's faction ambassador appears, sending him or her to the Vermillion Redoubt to gain the favor of the members of the red dragonflight near Grim Batol. The red flight is having problems of its own with the Twilight's Hammer, and the fight between the red and twilight flights escalates to the point that Alexstrasza and Deathwing both make appearances!

To the Twilight Gate.

Upon completion of Last of Her Kind in the Obsidian Forest, adventurers are sent to their faction's forward camp just outside the Twilight Gate to take on the Twilight's Hammer forces guarding the Twilight Citadel and the Bastion of Twilight. In an attempt to end the Twilight's Hammer problem once and for all, Mathias Shaw and Garona Halforcen are on a hunt for The Hammer of Twilight, an artifact commissioned by Deathwing and imbued with power by the Old Gods created for Cho'gall's use.

Completing this quest chain awards the achievement King of the Mountain

The Ring of Blood of the Twilight Highlands takes place at the Crucible of Carnage. This is an entirely optional side chain, designed for five players. It awards the best weapons found outside of instances. Completing this quest chain awards the achievement Round Three. Fight! and is necessary for the achievement The First Rule of Ring of Blood is You Don't Talk About Ring of Blood.