The Walls of Absence (audio story)

 was the first story in the audio anthology Solitary Confinement, produced by Big Finish Productions. It was written by James Goss and featured Derek Jacobi as the War Master.

Publisher's summary
The Code Purgers of Chift have made a fortune cleaning up the galaxy’s code: subroutines assessed, and errors repaired. So when the Master loses his mind, quite literally, there is only one place he can turn.

Plot
to be added

Cast
to be added
 * The Master - Derek Jacobi
 * Mendrix - Siân Phillips

Continuity
to be added