Those scenes where the baddies chasing James Bond fall off a mountain-top are, understandably enough, enacted by dummies. 'The Most Dangerous Jump in the World' - from the top of a 6,237ft cliff-face - is undertaken by real people, though you might still feel justified in calling them dummies. Tonight's VOYAGER (7.30pm ITV), the first in a seven-part series of sumptuously photographed National Geographic films, charts the efforts of Australians Nic Feteris and Glenn Singleman to break new ground. Their aim is a Base (building, antenna, span, earth) jump from the top of the Great Trango Tower cliffs in Pakistan. Nic is an experienced jumper (read, adrenalin junkie) who avers: 'I need to have my life at volume 10 rather than volume one and a half. I like to have it in vivid colours.' Glenn, a seasoned mountaineer, is not entirely sure what he's letting himself in for: 'Falling off a mountain goes against all my instincts as a climber.' They teach each other their respective skills; as Glenn puts it: 'I'll get him up and he'll get me down.' After 12 months' preparation, they trek off for a stunt that even Sylvester (Cliffhanger) Stallone might blench at.