Jimmy Carr, Sean Lock and Jon Richardson take on the famous words and numbers quiz in a special Channel 4 "mash-up." Jimmy Carr hosts proceedings, and Sean Lock faces Jon Richardson in a celebration of Channel 4's 30th Birthday. Joe Wilkinson is in Dictionary Corner along with Countdown regular Susie Dent. Meanwhile the country's favourite boffin Rachel Riley provides the letters and numbers.
| Name | Type | Role | |
|---|---|---|---|
| Joe Wilkinson | Guest Star |