River of Blue Fire – Tad Williams
Otherland is civilisation’s most stunning achievement: a private, multi-dimensional universe built by the greatest minds of the twenty-first century. But this most exclusive of places is also a jealously guarded secret, created and controlled by the Grail Brotherhood, a private cartel known to a few and made up of the world’s most powerful and ruthless individuals.
The purpose of Other is still a mystery. But it may not remain so for long. For a small band of adventurers has penetrated the secrecy that surrounds it and has broken into the amazing worlds with worlds it contains. However, with one among their number determined to ensure that no one lives long enough to reveal the truth about Otherland, an extraordinary quest soon becomes a desperate race against time.