Curse of the Worgen
Three days before the Worgen Curse began to emerge across Gilneas, Mia was inside the Greymane Manor when Cox, who was Halford Ramsey's partner, arrived to the manor and informed the news to King Genn Greymane of Ramsay's death, but in truth, Halford was alive and became one of the feral worgen. Eventually, when the curse began to spread, Mia remained untouched while nearly all of the inhabitants, including her husband, were infected by the curse and turned into worgen. When the Shattering erupted and the Forsaken began to invade Gilneas under the command of Sylvanas Windrunner, Mia would witness an argument between her husband and Lord Vincent Godfrey about how Darius Crowley and his followers, who were turned into worgen, were released ever since the end of the Northgate Rebellion. That was when she noticed the arrivial of a large number of Gilnean evacuees that had arrived to the Greymane Manor after Duskhaven was destroyed.
This section concerns content exclusive to Cataclysm.
After the citizens had to evacuate Duskhaven during the cataclysm, Mia managed to calm everyone and not to panic. She would also send a worgen adventurer to meet her husband and to inform him that it was time to evacuate manor in carriages. Mia evacuated with her daughter with the evacuees when the Night elves came to their aid. However, she would soon learn that her son Liam was killed by the Banshee Queen Sylvanas Windrunner.
Lord of His Pack
During the venture to Darnassus, Mia and her daughter Tess were stationed aboard the Elune's Radiance with a group of Gilneans while Genn was on another ship. When a powerful storm hit the Elune's Radiance and started to sink, Mia's leg was broken and could not move while her daughter remained with her. Mia pleaded her daughter to go, but Tess refused to leave, so they both risked drowning while the Gilnean evacuees that were onboard the Elune's Radiance were rescued by Night elves and Worgen. Before Mia and Tess were about to meet their end, Genn managed to rescue them while in his worgen form and refusing to lose the last two members of his family. Once the storm was over, Mia's leg was healed by a group of Night elf druids and reached Teldrassil safely.
Battle for Azeroth
This section concerns content exclusive to Battle for Azeroth.
While Genn is forced to remain in Stormwind City during the War of the Thorns, Mia leaves his side to travel to Darnassus. While her initial focus is to rescue fellow worgen from the Horde's attack, she remains in order to assist the night elves with their own evacuation. She ignores Genn's repeated pleadings to return to Stormwind, eventually becoming trapped after Sylvanas Windrunner lights Teldrassil on fire.
Genn, disobeying Anduin Wrynn's direct order, leaps through the portal and into Darnassus. There, he finds her cradling a child, rescuing them both before the portals close for good.
Patch 4.0.3a (2010-11-23): Added.