Visually the dark scripture was a book bound in a maroon leathery material scripture with a golden rune symbol on the cover and golden spiked corner bindings.[Defiance][Defiance/10]
"As the handsome coffin hides the putrefying corpse within, the great Cathedral of Avernus seemed to hold its own secrets, hidden in the catacombs beneath its vaulted chambers. Was this the source of the corruption that infected Nosgoth? Vorador had hinted at something more."
The Dark Scripture is explicitly named as such in the inventory and its name is reiterated in the official guide. In game files the Dark Scripture is labelled as "av_altarkey". A corresponding 'lock' texture labelled as "av_altarlock" is included in files but consists mainly of effects and does not include the altar itself which is counted as part of the environment. Curiously the 'lock' textures also include an image which appears to be the cut Blue Chalice.[Defiance][Defiance/10][Defiance/11][Defiance/12]