Every summer a group of hardy competitors gather in the Isle of Man to take part in a race so dangerous that mainstream motorcycling has turned its back on it. Since the Isle of Man TT was first held in 1907, more than 230 riders have died while attempting to complete a treacherous course on public roads that plunge through towns and over mountains.
The idea of a 3D film devoted to this subject would normally be enough to send yours truly into a deep sleep, but Richard de Aragues' TT3D: Closer to the Edge turns out to be a gripping, shocking, well-made and very funny fly-on-the-wall documentary.
Most of the humour comes courtesy of Guy Martin, a charismatic, shaggy-haired, foul-mouthed young man who's the kind of character other sports can only dream of.
Mr Martin has never actually won a TT race, and in TT3D we follow him and fellow competitors including John McGuinness, Ian Hutchinson and Northern Ireland's Michael Dunlop (nephew of the famous Joey) as they converge on the Isle of Man to prepare themselves for the 2010 TT race. Mr de Aragues uses bike-mounted cameras to give us some idea of the terrifying speeds at which these men race around the island and launch themselves into hairpin corners knowing that the slightest miscalculation could lead to severe injury or death.
It would be very easy to dismiss as idiots men who knowingly expose themselves to the strong possibility of horrific disfigurement or death on a regular basis: many of them have families, and a rider who died in the 2010 TT left behind two kids and a wife who pretends to be philosophical about it.
But the TT men are undeniably brave: they're testing themselves in extreme circumstances, and clearly love a sport that they all describe as an addictive high. Mr Martin describes it most colourfully, and his constant battles with authority and himself help make TT3D a very enjoyable experience
Day & Night