It should be simple. A delegation from Rio de Janeiro is in town and the Olympic Deliverance Commission has to greet them at their Mayfair hotel then coach them out east to the London 2012 site for lunch with Sebastian Coe. Unfortunately, the driver is more familiar with Nottingham, and satire steers into farce as the coach plunges twice into the Blackwall Tunnel before bombing up the M11. As this ODC odyssey unfolds, team boss Ian (Hugh Bonneville) remains resolutely tactful and tactical, while a no-nonsense Portuguese interpreter (Karina Fernandez) translates Ian and co's diversionary flannel as she sees fit. Perhaps funniest of all is Head of Sustainability Kay Hope (superb Amelia Bullmore), who has to field irate calls from the school of her scissor-happy son: "He's a very imaginative boy. You are aware of that?" Kudos, too, to Coe, whose cameo lends the whole show credibility.