For some reason, we've been putting off watching this - and, suddenly, it's the last in the series. The Top Gear presenter travels to the North Sea, 50 miles offshore from Bergen, Norway, to explore the technology of the Troll A natural gas platform. Richard learns how the construction, the largest object ever moved across the Earth by man, owes its design to a pioneering 19th-century engineer, a 17th-century German mayor and a turbocharger used by Marcel Renault in a 1902 motor race. Hidden in its DNA, he finds a crystal glass, a farm building, a racing car, a plant pot and nothing! If you're toying with the idea of watching tonight's Top Gear repeat (7.10pm), it's the one with the Alpha Romeos and *sighs* James 'You Can't Escape My Potato Head' Corden.