| A mock-documentary following the challenges - both personal and professional - faced by the team responsible for delivering the biggest show on Earth: the 2012 Olympics. From getting a busload of non-English speaking Brazilians from A to B, who to appoint to run the Cultural Olympiad and what to do when the much-vaunted wind turbines won't turn because there's no wind, it's all in a day's work for the men and women whose job it is to stage the greatest sporting event in the world. |
| Name | Character | Episodes |
|---|---|---|
| David Tennant | Narrator (voice) | 13 |
| Olivia Colman | Sally Owen | 13 |
| Hugh Bonneville | Ian Fletcher | 13 |
| Jessica Hynes | Siobhan Sharpe | 13 |
| Amelia Bullmore | Kay Hope | 13 |
| Vincent Franklin | Nick Jowett | 13 |
| Karl Theobald | Graham Hitchens | 13 |
| Alex Beckett | Barney Lumsden | 8 |
| Morven Christie | Fi Healey | 7 |
| Joel Fry | Karl Marx | 7 |
| Samuel Barnett | Daniel Stroud | 7 |
| Sara Pascoe | Coco Lomax | 7 |
| Simon Wilson | TV Reporter - Sam | 3 |
| Tim McInnerny | Tony Ward | 1 |
| Eleanor Matsuura | Doctor | 1 |
| Nicholas Jones | Tony Griffiths | 1 |
| Johann Myers | Fidel Wilson | 1 |
| Nina Sosanya | Nina Christiani | 1 |
| Jason Watkins | Richard Salter | 1 |
| Christopher Fulford | Commander Bob Burford | 1 |
| Mark Bonnar | Ben Farrell | 1 |
| Martin McDougall | Senior Operations Analyst Scott Coldwell | 1 |
| Georgie Glen | School Receptionist | 1 |
| Bentley Kalu | Senior Clandestine Logistics Officer Ryan Burr | 1 |
| Darren Boyd | Dave Wellbeck | 1 |
| Vicki Pepperdine | Sarah Slocombe | 1 |
| Frankie McCafferty | Brian McLoughlin | 1 |
| Jessica Knappett | Carey Taylor | 1 |
| Martin Marquez | Kevin Thingie | 1 |
| Nicholas Gleaves | Anthony Preston | 1 |
| Tim Bentinck | Richard Parker | 1 |
| Ingrid Oliver | AP The Today Programme | 1 |
| Jimmy Akingbola | Receptionist | 1 |
| Tom Riley | Christian Jebb | 1 |
| Nitin Ganatra | Martin Soper | 1 |
| Philip Arditti | Saleem Ahmed | 1 |
| Demetri Goritsas | Max Madeley | 1 |
| John Hollingworth | Reporter | 1 |
| Paul Hilton | Jason Topper | 1 |
| Marcus Onilude | Shaquille Johnson | 1 |
| Lucy Briers | Laura Fletcher | 1 |
| Lucy Briers | Anna Mitchell | 1 |
| Jalaal Hartley | Ben Hooper | 1 |
| Selina Griffiths | Anna Priestley | 1 |
| Chizzy Akudolu | Jane Owen | 1 |
| John Ramm | Nigel Fox | 1 |
| Jonny Sweet | Justin Carter | 1 |
| Kate Silverton | Herself | 1 |
| Neil Edmond | Mike Whitaker | 1 |
| Karina Fernandez | Interpretor | 1 |
| Kim Wall | Paul Bavington | 1 |
| Jamie Dispirito | Ben | 1 |
| Robin Weaver | Deputy Asst. Commissioner Rachel Crane | 1 |
| Karina Fernandez | 0 |