The heroes of the Alliance recognized their impending doom, and began to discuss their more desperate options. Hard decisions were made, and various options were discussed. Assets that had been committed to making their homelands livable were instead assigned to exploration efforts and refugee support, in the hopes that a new region could be found for these homeless. At the same time, they prepared to make whatever sacrifices might be necessary in order to delay or deter the invasion's progress.
Ultimately, the leadership council decided that the only possible hope for victory would be to slay the Witches directly. Most of the council members believed that if the Witches were slain, their banes and Accursed would crumble to dust. A few suspected that the loss of even one Witch—who were believed immortal—could be enough to deter the others from pressing their attack.
A plan was hatched, in conjunction with the Seelie Fey. The Fey had played only a minor role during the invasion to date. Though both sides had attempted to recruit their assistance, the fickle beings had chosen to avoid direct participation in the war. However, as the Witches continued to destroy vast swatches of Morden, the Seelie wept at the wanton loss of life and natural beauty. The capricious entities decided that it was time to commit to stopping the Witches.
After negotiations and planning were complete, the Fey made a false offer to ally with the Witches. The Witches knew well of their power, and recognized it, though they also knew not to trust the unpredictable creatures. As creatures of magic, the Seelie could provide a tremendous level of support to the Witches, and even offer transportation to the invading forces through their otherworld—the Summerlands. The invaders were naturally suspicious of the offer of alliance, but accepted it with reservations. The potential for benefit drew their greed, and overcame their reluctance and concern.
After a few initial sorties to build trust, the Fey began working with the Grand Coven to direct a final dramatic action, designed to finally eliminate all human resistance. Most of the Witches marshaled their forces, preparing a major offensive that could roll across the Ash Plains. At the same time, the Djinn took command of the reserves. She directed them on a drive through the Summerlands, so that they could strike directly at Manreia. During their hurried march, the Seelie Fey—in conjunction with the heroes of the Alliance—revealed their treachery.
While the armies of the Alliance fought a holding action against the Witch armies in the Ash Plains, the heroes and elite units had lain hidden in the Summerlands. As the Djinn and her forces passed by, the armies of Morden unleashed an attack. In the course of the battle, King Auberon's blade pierced the Djinn's ethereal flesh. A massive blast of uncontrolled magic was unleashed as the two forces came into contact.
In an instant, an enormous surge of magical energy passed between the otherworldly Summerlands and the physical world of Morden. The wave of energy killed tens of thousands who fought in the Ash Plains—on both sides of the conflict. Some who had fought in the Summerland's battle were spontaneously transported back to Morden. Others vanished from the physical world with no explanation—whether they travelled to the Summerlands, elsewhere, or were simply vaporized is unknown.
Since the Betrayal, there has been no further contact with the Summerlands, the Seelie Fey, or the Djinn. Not even the Unseelie Fey or the surviving Witches know the ultimate fate of those who vanished during the battle. In the end, this battle proved enough to end the war, though not in quite the way the Alliance had intended.
Recognizing their mortality, the remaining Witches lost their thirst for conflict. Many blamed each other for the mistake in allying with the Fey and for the apparent death of their sister, the Djinn. More than half of the Witches took their armies with them and retreated back beyond the Darkfall Peaks. Five remained behind, securing their hold over the nations of Morden. After all, without the leaders who had vanished in the final battle, there were no human armies to protect the remaining nations.