The Great Houses kept a records library in a labyrinth buried in the framework beneath normal-time. It was used as a backup for classified data because everything in it remained unaffected by timeline changes. The information was kept in hundreds of thousands of hard-cover books. Mr Smith, the library's bull-headed librarian, was an extension of the labyrinth and side-effect of the temporal engineering which created it.
Contents of the library included Rudyard Kipling's Days of Other Empires, Lewis Carroll's third Alice in Wonderland novel, an aesthetically coded book left by Morlock, the Chapterhouse records of House Lolita, and the Scarlet Chapterhouse collection, which contained the secret minutes of House Dvora that revealed who killed Umbaste.
Before the War in Heaven, all Great Houses installations had links to the library. These links became a liability during the War, and in the conflict's sixth decade caused its destruction. Justine, Shuncucker, and Veeble escaped to the library during the chaotic breakout at the Houses' prison planet organised by the Blood Coteries, followed by Demetra Kine's trackers. In the ensuing fight, Shuncucker overcame the creatures' invulnerability to shadow-weapons by using a shadow-flamethrower to light the books on fire so that the creatures would be burned by the books. The fire quickly spread through the library. (AUDIO: A Labyrinth of Histories)