It'll be a laugh," my producer Garth told me when I asked him to remind me why I'd agreed to do this. And to be honest, I have been struggling to remember.
The last time I stood in front of a room full of strangers and told jokes was at a corporate awards do and I nearly got booed off stage for a misjudged joke about orphans in Africa.
As I see it, there are four things working against me:
1) I have never done this before.
2) I won't be making my stand-up debut in front of an audience that have come to see me. I'll be making my stand-up debut in front of an audience that have come to see Reginald D Hunter. Arguably, Edinburgh's most respected turn. He'll introduce me to his 400-strong crowd at the end of his show. Every comic that I have explained this to has recoiled in horror.
3) As a regular Edinburgh Festival goer, I know that no matter how good a show is, when that hour is up you are ready to leave. Always. Every time. One hour in an uncomfortable, usually hot, Edinburgh venue is quite enough.
4) My mini-set will be broadcast live on BBC Radio 5 Live. This places upon it restrictions alien to stand-up. I can't swear. I cant do jokes about politics. Or God. Or alcohol. Imagine doing an open-mic spot for the Taliban. Although sexism's also out.
Please don't read those as some kind of excuse. I am not claiming that without those compromises I would be some kind of natural. I wouldn't. Each year's visit to the festival increases my respect for the job of stand-up comedian, exemplified by the brilliance of some of the shows I have seen this year. Colin Hoult's Carnival of Monsters. John Bishop. Richard Herring. Paul Sinha. Sarah Millican and so many others. And actually I have now remembered why I agreed to do this. It's exciting. It's really exciting.
You can hear Richard Bacon on Radio 5 Live tonight from 10pm (bbc.co.uk/5live)