Jimmy Carr hosts and regular Countdown mathematician Rachel Riley and lexicographer Susie Dent are on hand to adjudicate Alan Carr and Harriet Kemsley play against Jonathan Ross and Maisie Adam. Huge Davies is in Dictionary Corner.

Jimmy Carr hosts the comedy words-and-numbers quiz as Richard Ayoade and Sara Pascoe take on Jon Richardson and Chris McCausland. Regular Countdown mathematician Rachel Riley and lexicographer Susie Dent are on hand to adjudicate, aided by Morgana Robinson in Dictionary Corner.