Thursday evening, 11pm. The most incredible entertainment event of the decade is about to begin, as Mark Watson takes the stage at the Pleasance Theatre in London. The audience is anticipating something special, but nobody knows exactly what – least of all Mark. This is because for the next 25 hours, until midnight on Friday, Mark will be on this stage doing comedy. For the whole day straight. No stopping, no breaks (except for weeing, and sometimes not even then), just 25 hours of laughing. He’s not alone in this endeavour, of course – TV’s Emma Kennedy joins him very early on, and spends the entire show on stage in a tent, whilst the winner of the Least Pronounceable Name In Comedy award Tiernan Douieb will be at the back learning to play piano, whilst getting hit in the face every hour with an increasingly larger custard pie. These three will be our core players and our stalwarts for the duration of the show, but they will be joined by numerous comedy guests, be it in person, via Skype or on the phone. Why? Because this is Mark Watson’s 25 Hour Comedy Marathon for Comic Relief, and what he says goes.