In the mean time, check out the great Shadeglass site. And this information from Games Workshop’s Warhammer Underworlds site:
THE CITY OF SHADESPIRE
Shadespire was once a city of wonder and magic, a mercantile metropolis rising from the unforgiving earth of the Realm of Death. Countless races dwelt within its walls, together creating artefacts of astonishing beauty and power. The city’s most treasured secret was the process of refining shadeglass, a miraculous substance that could store the spiritual essence of the dead for eternity. In this way, the ruling Katophranes of Shadespire lived on after death, their wisdom stored within the depths of ornate mirrors, flowing glass fountains, crystal looking‐stones and other marvels. This defiance enraged Nagash, Lord of Undeath, who sought to punish the occupants of the city for denying him his rightful tithe of souls.
Yet to simply destroy the city and drag its inhabitants to the Underworlds seemed to Nagash an insufficient punishment. Instead, the Great Necromancer wove a ritual that drew upon the mysterious powers of the city’s shadeglass constructions, siphoning away the light and glory of Shadespire and creating a twisted reflection of its former splendour. Shadespire was trapped halfway between Ulgu – Realm of Shadows – and Hysh – Realm of Light. Bound within this dark reflection, refracted between these two diametrically opposed realms, the souls of the fallen could never escape the Mirrored City and make the journey to the Underworlds. None within its walls would be granted the release of death. Nagash would forever deny them that gift.
The Mirrored City of Shadespire is a nightmare plane of illusions and madness, an ever-changing labyrinth of endless stairs, cramped streets and soaring archways. The original city is drained of all colour and life, and for thousands of years, it has rested as a foreboding ruin. Those unfortunate, brave, or foolhardy adventurers that set foot within its walls are drawn through the veil between realms and trapped within the Mirrored City. For such wayward souls, all hope seems lost. Yet there are those who will not accept their fate without a fight.
For more than a thousand years the shadow-cloaked ruins of Shadespire lay dormant, a malevolent scar in the centre of the vast Desert of Bones. During much of that time there were few fresh victims of the city’s terrible curse. Travellers seldom ventured across the deadly, parching wastes to reach the city, as often warded away by the lethal storms that wracked its bone-dust dunes as by the dark stories that had sprung up around the place. Yet some were brave or foolish enough to stray within the borders of the cursed city, and those fortunate few who returned brought back priceless treasures and forbidden knowledge, as well as rumours of haunted mirrors, nightmarish illusions and other strange tales.
Some of those now trapped in Shadespire are noble souls, determined to end the curse and deny their fate. Others are savage brutes, for whom an endless cycle of violence is its own reward. There are avaricious looters, frenzied barbarians and sages whose desire for knowledge has led them down dark paths. These disparate souls will clash together as each attempts to escape damnation, and the haunted streets of Shadespire will run red with blood.
A Place of Reflection (Amazon UK)
Moribus, Stormcast Eternals Decimator of the Sons of Mallus, wanders the glass labyrinths of Shadespire alone. Somewhere out of sight, his brothers can be heard, and together they search for a dangerous creature, a malignant spirit that haunts this wasteland. This foe carries a cache of shardglass, which Sigmar hopes can cure the Stormcast Eternals of the degradations that come with their reforging. As Moribus remembers his many deaths to focus his mind, he begins to doubt his senses and reality – and danger beckons.
Doombound (Amazon UK)
In the cursed city of Shadespire, two Stormcast Eternals Liberators, Darras Sunblade and Erak Grimwatch, seek a way to rejoin their comrades in Severin Steelheart’s company. However, the twisting and ever-changing maze of the dead city thwarts them at every turn – and Grimwatch has his own troubles as flashes of another life take him.
Mortal danger stalks them, as a warrior of the Khorne Bloodbound, also suffering visions of an impossible past, seeks to take their skulls for his bloodthirsty god….
The Autumn Prince (Amazon UK)
Lured into the cursed city of Shadespire by the promise of the secret of cheating death, the aelf wanderer Prince Maesa seeks the Katophrane Thanaton. Surrounded by the spirits of the dead who cannot die, trapped in the last moments before the city’s destruction, Maesa nears his goal…but just why does a nigh-immortal aelf seek this power over death?