The vengeance of the burning shadow has come.
- Archmage Khadgar
The Broken Isles Campaign is the war on the Broken Isles, the epicenter of the Burning Legion's third invasion of Azeroth. Its combatants are the combined forces of Azeroth and the demons of the Burning Legion, across the Broken Isles. The campaign's first battle was the Battle of the Broken Shore, which ended in disaster for the Alliance, Horde, and Argent Crusade with the deaths of their leaders, Varian Wrynn, Vol'jin, and Tirion Fordring. After various invasions across Kalimdor and the Eastern Kingdoms, the forces of Azeroth returned to the Broken Isles, where they began to drive back not only the Burning Legion, but also their allies and other old or new enemies. The forces of Azeroth now scour the Broken Isles in search of the Pillars of Creation, the only thing that can seal the portal allowing the Burning Legion to enter Azeroth at the Tomb of Sargeras.

In Stormheim, the forces of Azeroth worked to claim the Aegis of Aggrammar by passing various trials to be deemed worthy by Odyn. However, along the way they face an enemy, God-King Skovald, who has allied himself with the Burning Legion, and is also trying to pass the trials to claim the Aegis. After passing the trials, a small group of adventurers entered the Halls of Valor, where they proved themselves before Odyn and took the Aegis of Aggrammar to Dalaran.

In Highmountain, the Underking Dargrul has stolen the Hammer of Khaz'goroth, a Pillar of Creation, shortly after the Battle of the Broken Shore. He then began to assault the Highmountain tauren, starting with an assault on Riverbend. After uniting the Highmountain tribes, except for the Bloodtotem who allied themselves with the Burning Legion and were therefore disposed of and replaced by the Stonedark drogbar, the Highmountain tauren and their drogbar allies took the fight to the Underking at Snowblind Mesa. There, a battle was fought, and the Highmountain tribes emerged victorious as Dargrul retreated into Neltharion's Lair, where he was finished off by a small group of heroes, and the Hammer of Khaz'goroth was secured.

In Val'sharah, Malfurion Stormrage has arrived in Lor'lathil, and rode to the Grove of Cenarius, where it is found out that the demigod Cenarius has been corrupted by the Emerald Nightmare. After recalling the Archdruids of Lore and the Claw - the Archdruid of the Vale having been terminated after being corrupted by the Nightmare as well - they summoned Ysera, and around the same time Cenarius disappeared into the Nightmare. After Malfurion is captured by Xavius, Ysera attempts to aid the druid, however she is corrupted by Xavius, and she soon attacks the Temple of Elune, where her life is ended, and she becomes a constellation. Upon her death, the Tear of Elune is retrieved and taken to Dalaran. Malfurion is freed from the Darkheart Thicket.

In Azsuna, the Illidari are found fighting the Legion forces at Falaanar, and after assisting them, the blue dragon Stellagosa is freed and she is met at the Azurewing Repose, where it is found out that Senegos, the oldest blue dragon alive, is dying. After repelling a Nightfallen invasion on the repose, Senegos is cured, and tells the heroes that a certain night elf prince, Farondis, knows the location of the next Pillar of Creation, the Tidestone of Golganneth. After going through Nar'thalas, and finding the Tidestone of Golganneth in the Nar'thalas Academy, Tidemistress Athissa steals it, and Farondis frees the adventurer that was captured by the naga. Then, with the combined forces of the Court of Farondis, Athissa is slain and the Tidestone of Golganneth is taken to the Eye of Azshara, where it is retrieved after the defeat of the Wrath of Azshara.

After becoming more powerful, heroes are sent to Suramar to help start the rebellion against Grand Magistrix Elisande alongside First Arcanist Thalyssra.