The Box of Delights
From Tardis Wiki, the free Doctor Who reference
The Box of Delights was a book, a copy of which was owned by Professor Chronotis. (PROSE: Shada)
Behind the scenes
In 2021, Big Finish Productions released an audio drama adaptation of The Box of Delights. It starred Derek Jacobi, Mark Gatiss, Louise Jameson, David Warner, Tim Bentinck, Mina Anwar, Lisa Bowerman, Raj Ghatak, and Annette Badland.