Sherlock and The Hobbit star Martin Freeman is to join a host of celebrities on Comic Relief's Big Chat with Graham Norton, where the talk show king will attempt to set a Guinness World Record for 'Most Questions Asked on a TV Chat Show'.
Other guests will include comedians Ronnie Corbett, Jimmy Carr, Lee Mack, Keith Lemon and Radio Times columnist Sarah Millican.
Also appearing are actors James Nesbitt, Warwick Davis and Russell Tovey, model Elle Macpherson, presenters Paddy McGuinness, Alex Jones, Steve Jones and Kirstie Allsopp, and celebrity chef Heston Blumenthal.
Completing the line-up are Got To Dance judges Ashley Banjo and Kimberley Wyatt, JLS singer Aston Merrigold and gymnast Louis Smith, with musical performances from Example, Paloma Faith, Hurts and Laura Mvula.
And as if that wasn't enough, Norton's support team of co-hosts includes chat-show veterans Sir Terry Wogan and Frank Skinner, alongside Radio 1's Nick Grimshaw and Greg James.
Speaking about his world record attempt, Norton said: "David Walliams swam the Thames, John Bishop endured a week of hell and Eddie Izzard ran marathon after marathon after marathon. I am hoping to join this elite group of celebrity fundraisers by doing what I do best – sitting on my backside and talking."
The BBC3 show kicks off at 7pm on Thursday 7 March and continues for the entire evening.
Viewers wanting to help Graham raise funds for Comic Relief can donate either £5 or £10 by texting FIVE or TEN to 70510. And if you have a question you'd like him to ask one of his many guests, you can submit them via Twitter (@bbcthree #bigchat) or by visiting the BBC3 Facebook page.