When Russell T Davies ripped up the TV rulebook with his pioneering 1999 Channel 4 drama, Queer As Folk, about gay pals in Manchester, he was left with a slightly unfinished feeling. At no point across the show's ten episodes was the word 'AIDS' mentioned. It has taken Davies another couple of decades to get there, but with the five-part It's a Sin he's confronting head-on the crisis which gave tabloids and certain politicians a field day in demonising gay men.

Set in London, beginning in 1981 and travelling into the early 90s, we follow a group of pals who have converged in the metropolis from different parts of the UK (Wales, Scotland and the Isle of Wight among them) to live out their dreams in wild abandonment only to find them crumble into a nightmare as HIV and AIDS close in. With a typical Davies flourish, there is pulsating sex and period music aplenty (the two combine amusingly in one rampant scene scored by Hooked on Classics), while a firm two fingers are stuck into the establishment's face; this era was ruled by the Thatcher government and its draconian homophobic censorship of Section 28.

Although there is a selection of acting royalty involved (Stephen Fry as a creepy Tory politician, Neil Patrick Harris' menswear clerk who succumbs to the disease, and Keeley Hawes playing a mother who refuses to confront the truth about her gay son), the main plaudits should deservedly go to its young cast. Among the stars here are Olly Alexander of the band Years & Years (not to be confused with Russell T Davies' 2019 drama of the same name) leading the way as Ritchie, a would-be actor in full denial that the virus even exists, Lydia West as Ritchie's best friend Jill who is blamed for enabling his excesses, and Omari Douglas playing the flamboyant Roscoe who briefly manages to find himself a seat at the table of power and influence.

Despite being completed just before Covid struck, the resonances are almost spooky: frenzied decontaminating of skin and surfaces, masks and isolation wards, and above all the misinformation and conspiracy theories which run amok when an epidemic is beginning to spread. Some might view this as almost a quaint period piece when the charts were full of absolute bangers, gay people had to keep their true selves deep in the closet or risk losing homes and employment, and unadulterated fun came at a price. But perhaps this is Davies both squaring his own creative circle and handing out an ongoing health warning: according to UNAIDS figures, over half a million people continue to die from AIDS-related illness across the world. Now that is a sin.

Channel 4, starts Friday 22 January, 9pm; all episodes available on All 4 at 10pm.