A TV show which features vampires, werewolves and bartenders who can change into dogs, should not equal cult viewing for adults. Artificial blood, fangs and skin which burns – literally – in the sun are plot specifics which should, in theory, be reserved purely for the adolescent teen. But when you throw into the equation a telepathic hotpant-wearing waitress (Sookie Stackhouse), a 174-year-old southern JOBgent (Bill Compton) who casts a sexual spell over her, a powerful 6ft 4in vampire sheriff and the sexiest love triangle on TV, you can begin to see why True Blood is actually one for us adults.

Then there’s the incredibly stylish cinematography (the credits alone look like a Hieronymus Bosch painting); plotlines which simultaneously deal with politics (albeit fictional ones, the series is set just after the Vampire Rights Amendment has been passed which allows vampires to live freely in the US and Scandinavia); popular culture (Angelina Jolie has supposedly adopted a vampire baby) and the type of raw, realistic sex you’ve probably never seen on television. And suddenly you have a show – which is just about to show its fourth series on next Tuesday on Channel 4 – that revolutionised TV.

In fact, on its release in the US three years ago, it sent shockwaves through the fairly conservative country thanks to its graphic sex scenes, nudity and a barely disguised political subtext – vampire bashing standing in for homophobia and racism (the show’s opening credits feature the sign: “God hates fangs”). It now has a cult following of two million viewers in the UK, the first series produced $17 million in US DVD sales in its first week, has its own jewellery and make-up line and the lead actors have become worldwide stars.

Perhaps True Blood’s success is less surprising when you discover the man behind the show is Alan Ball; the genius who wrote the equally dark 1999 Oscar-winning film American Beauty and the lauded TV series Six Feet Under. Ball has a talent for challenging conventions and teasing viewers’ boundaries and immortal vampires, who possess a potent sexual energy which can send humans into a drug-like sexual high, and live a life without boundaries is the perfect vehicle for his dark and addictive vision. His vampires may be dead, and survive by drinking the blood of humans, but the viewer can still empathise and live their extreme lives vicariously.