From Discworld MUD Wiki
It appears as a shimmering grimoire.
Phasing in and out of reality, this lost grimoire sits here calmly passing the time. Odd that it should change colours and transparency. Its spine is decorated with what seems to be an rice-paper dragon and its pages are guilded in platinum specks.
The rice-paper dragon exhales octarine fumes slowly but steadily.
This book can appear in any of the four tome locations inside the library.