Dan Witchalls and Ian Richardson are addicted to the world's most deadly adrenaline sport: base jumping.

Cutting Edge follows one of Britain's most prolific base jumpers and his right-hand man as they jump from the top of some of the country's most famous landmarks and escape death by pulling their parachute just seconds from impact.

'Base' is a secretive, underground community that likes to play while the city sleeps, and the 'bandit jumpers', as Dan and Ian are known, cruise the streets, searching for buildings to sneak into, climb up and jump from. Dan and Ian have leapt from some of Britain's iconic structures, such as Nelson's Column, The Millenium Dome, Wembley Stadium and Blackpool Tower.

Dan and Ian explain that a successful jump gives an unbeatable high, but the lows are often fatal. One wrong turn or gust of wind can result in a very serious accident. Since base jumping was invented there have been 144 deaths, meaning one in six people who take up the sport are killed.

Dan is a natural athlete who has escaped serious injury in over 800 jumps, but the risks he's taking are spiralling to more dangerous extremes in search of thrills. Now, he even goes out on his own during the night on a 'base crawl', leaving his girlfriend to worry whether he will return.

Ian has earned a reputation among his jump buddies as being accident-prone. In 2009, he was almost killed when he smashed into the side of a building after his parachute opened incorrectly.

Film makers Rob Davis and Alastair Cook question the drive to keep going back to a sport that jeopardises their lives and also their relationships with their families and partners. Can they really marry the two or will they be forced to make a choice to decide their future? Every jump relies on an element of luck and these men know they are playing russian roulette, yet they cannot kick the habit.

With stunning and exhilarating images throughout, the documentary follows the spectacular jumping exploits and near-death experiences of Dan and Ian over the course of a year, seeking to gain psychological insight into the motivation behind one of the world's most dangerous sports.