Forbidding

The Forbidding is an alternate dimension contained within the Shannara series of books by Terry Brooks. It runs parallel to the dimension in which all of the races live, the Four Lands, meaning that the layout of the land is almost identical, although locations are given similar names (eg. Dragon's Teeth, Dragon Line). The Forbidding contains all of the Demons of the world, which were trapped there by the Elves in the Age of Faerie. Within Arborlon, the Elven capital, resides the Ellcrys, an Elf who has willingly given her life to serve in tree form, protecting and guarding the barrier between the Forbidding and the world of humanity.

Role in The Elfstones of Shannara

In Elfstones, the Forbidding was the central conflict of the book. The Ellcrys was dying, and therefore Demons were escaping, the most powerful first. When the Forbidding finally broke, the Demons arrived in Hoare Flats where the Elven army, warned by Allanon, was waiting. The Demons wanted to first ensure that no new Ellcrys could be born, so as soon as they got through the Forbidding, they set course for Arborlon and the Gardens of Life. Through sheer strength of numbers, the Elven phalanx was broken, and only the timely intervention of Allanon defeating a Dragon saved the army. Later, a new defensive strategy suggested by Stee Jans carried the day for the Elves, but a much larger army was found to be flanking them--forcing them to retreat. With their backs to the wall in Arborlon, the army was eventually pushed back to their final place of retreat--but Amberle Elessedil appeared then and became the new Ellcrys, shoving the Demons back into the Forbidding.

Role in High Druid of Shannara

In the High Druid trilogy, Grianne Ohmsford is transported to the Forbidding by rival Shadea a'Ru through the use of a magical potion called liquid-night. Grianne is trapped there for most of the series, until her nephew Pen is able to come and rescue her.