Monty Python's Big Red Book

A copy of the Monty Python book Monty Python's Big Red Book was one of the many volumes stored in the planet known as The Library. (DW: Silence in the Library)

Behind the scenes
Monty Python alumnus John Cleese made a cameo appearance in City of Death. Cleese remains, to date, the only Python to appear in a Doctor Who story. Minor Monty Python contributor Douglas Adams wrote or co-wrote several Doctor Who stories, including City of Death as well as serving as one of the series' Script Editor.