For thousands of years the Mythal has been in place upon Myth Drannor. Over these years the city has changed immensely, once a great city, Myth Drannor is now in ruin, and overrun by monsters. The Mythal has also changed, it's power to keep in the demons from the Nine Hells is weakening. When the Mythal falls the Baatezu and Tanar’ri that inhabit Myth Drannor will be able to leave the city and reek havoc on Toril. Bringing their internal Blood War to the Forgotten Realms.

One of the powerful wizards who originally weaved the Mythal has knowledge of this. The Elminster knows that the Mythal is weakening and he has begun to try to strengthen it and keep the demons inside of the ruined city. Since the weakening of the Mythal some demons have been able to gate more of their own kind into Myth Drannor, something that the Mythal normally allowed them not to do. This scares the old wizard and he is not sure if he can undertake this task alone. When he originally set the Mythal around Myth Drannor he had a number of powerful mages help him, and unfortunately since the fall of Myth Drannor those wizards have disappeared. For the sake of Toril, the Elminster must find a way. But as he does this the forces of evil move.

A race of evil beings from the Lower planes, known as the Yugoloths also see what is happening in Myth Drannor. They see the power that they can gain from the magic of Myth Drannor and the devastation they can inflict on the people of Toril if the Mythal is destroyed.  One Yugoloth in particular wishes to harness the power of Myth Drannor for his own evil plots. This Ultroloth and his minions have begun to try to access the magic to finally destroy the Mythal. The Ultroloth works for a Pit fiend, named Nuleerdra who also wishes to see the destruction of the Mythal and to bring the Blood War to Toril. Whether these two evil beings can work together is yet to seen. But other forces of evil also have begun to move. The Tanar’ri will not ideally stand by and watch the Baatezu gain power to use against them. The Alhoon and Phaerimin also gather their forces. Human groups like the Cult of the Frost are also involved. They seek the Crystals of Ice which are located in Myth Drannor. They have been searching for these crystals for decades and finally know there location. These crystals would allow the Cult of Frost to cover the Dales with ice. The Ultroloth also wants to get his hands on the crystals. For they hold some of the power that he and Nuleerdra need to destroy the Mythal.

A band of adventurers have stumbled upon the Cult's plots and are about to be caught in a struggle to stop the Blood War from coming to Myth Drannor. This band is known as the Northern Knights and hail from the city of Silverton in Mistledale. Can they capture the crystals before the Cult of Frost does ? Can they stop the Blood War from coming to Toril ? Can they survive to see the outcome ? We will see.