Although this was Terry Pratchett's speech, the majority of it was read by Tony Robinson due to side-effects of Pratchett's Alzheimer's making reading aloud difficult.
Present in the audience are actors Jeremy Irons, Nigel Planer and Marc Warren. Each had previously been in TV adaptations of Pratchett's novels. Irons played the Patrician in The Color of Magic (2008), Warren played Teatime in Hogfather (2006) and Planer was in both productions, as well as narrating various Discworld audiobooks and voice acting in the computer games Discworld II: Mortality Bytes! (1996) and Discworld Noir (1999). Tony Robinson, who delivers the lecture, was also in Hogfather (2006), narrated Discworld audiobooks and voice acted in the computer game Discworld (1995).