Jimmy Carr hosts this edition with captain Jon Richardson and special guest captain Lee Mack who are joined by celebrity guests Bob Mortimer and Adam Hills. Countdown regular Susie Dent is in Dictionary Corner with help from Alex Horne and the Horne Section while the country's favourite boffin, Rachel Riley, provides the letters and numbers with a little help from comedian Joe Wilkinson.

Jimmy Carr hosts the Cats/Countdown mash-up, with Sean Lock, Jon Richardson, Bob Mortimer and Richard Osman. Matthew Crosby joins Susie Dent in Dictionary Corner, and Joe Wilkinson 'helps' Rachel.

Sean Lock and Bob Mortimer take on Jon Richardson and Holly Walsh. Isy Suttie's in Dictionary Corner with Susie Dent. Claudia Winkleman stands in for Rachel Riley on letters-and-numbers duty.