5. Lee Mack, Bob Mortimer, Adam Hills, Alex Horne and The Horne Section

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.