Siberia: Comedic chums Ed Byrne and Andy Parsons brave freezing temperatures as they drive across Siberia's infamous Road of Bones, encountering icy tracks and deserted gulags. [S]
Ho Chi Minh Trail: Sue Perkins and Liza Tarbuck have to dodge unexploded bombs as they tackle the Ho Chi Minh Trail, a mazy network of dangerous roads through Laos and Vietnam. [S]
Ethiopia: Comedians Hugh Dennis and David Baddiel are shaking to their funny bones as they drive 2,000km along Ethiopia's bumpy roads in a quest to find the Ark of the Covenant! [S]
Nepal: Comedians Rhod Gilbert and Greg Davies won't be laughing too much as they dodge reckless drivers, floods and landslides on an ambitious drive through mountainous Nepal. [S]
Alaska: And you thought the M25 was bad. Sue Perkins and Charley Boorman trek across Alaska on the notorious Dalton Highway, battling Arctic conditions on a glorified dirt track. [S]