The hit BBC mockumentary has stopped playing up Kurupt FM’s ineptitude and swapped it for something far sadder. It’s a brave move – and as Grindah, Chabuddy and co sink to new lows, this show soars ever higher

Grindah’s not looking too great. Kurupt FM’s head honcho is crashing with pal Steves after his breakup from fiancee Miche, gurning and unkempt as he flits between making threatening phone calls to a rival radio station and bingeing on drugs. He stammers as he orders his friends to move Kurupt FM’s equipment into a storage unit, panicked and paranoid. “It’s good to have someone to do drugs with,” says Steves of his friend’s decline. “A lot of people get weirded out by me and leave, but he’s got nowhere to go”. Ten minutes into its latest series, and People Just Do Nothing looks more like a Channel 5 doc on the dangers of spice than a Bafta-winning mockumentary.

Facebook Twitter Pinterest Chabuddy G’s fall is the most tragic of all. Photograph: BBC/Roughcut/Jack Barnes

Now on its fourth run, PJDN has long been praised for its portrayal of life in West London suburbia, a place that – as many a resident past or present will attest – often feels a million miles from the buzz of the city. And, parallel to the central plot of Beats, Grindah and co’s unstarry existence as small-time garage MCs, the show’s cast have become stars in their own right, playing festivals in the UK and abroad, with a takeover of London’s Roundhouse planned for next month. It’s perhaps surprising, then, that series four has seen the show delve ever further into sadcom territory – popularised by the likes of Master of None, Bojack Horseman and Fleabag – as it increasingly examines the difficulties its protagonists face rather than playing up their ineptitude for lols.

Following a tearjerking season three finale where Steves’ nan died, we’ve seen Miche and Grindah’s breakup and subsequent, underwhelming reconciliation (“Nothing screams class like a lasagne,” declares Grindah as he tries to trick her into thinking he’s changed for good); Miche fill a void by turning her daughter Angel into a child star, morphing a school play audition into an episode of the X Factor; Steves convince himself that his nan’s spirit lives on in Beats and Roche’s baby; and Chabuddy G slide into poverty and homelessness.

Chabuddy’s fall is the most tragic of all, the all-seeing mockumentary camera following the serial entrepreneur as he beavers away in the stockroom of a high street electrical shop where he is known, in a case of awkward cultural assimilation, as “Charlie” – before retiring to his van. There was always a heartbreaking edge to Chabuddy’s existence (this is a man whose mail order bride robbed him blind before fleeing with her “brother”) but we had never seen him truly lose it all, living in a Renault Trafic with a bucket for a toilet. More than ever, PJDN is a show about people chasing the dream of “making it” and instead falling flat on their faces. But it is always loving rather than condescending in showing working-class ambition and the pursuit of fame, something this series has only made clearer.

Facebook Twitter Pinterest Poor Miche… Photograph: BBC/Roughcut/Jack Barnes

As we reach the finale, there’s an ominous mood in the air – one which in previous seasons may well have already been undercut by banter or bathos. Grindah has overcome his temptation to cheat on Miche with a stripper during his bachelor party to a soundtrack of Ginuwine’s Pony, while Miche has had her heavily stage-managed hen do overruled by drunk pals. The pair ended episode five describing quite different versions of their future together (Miche: big house, more kids; Grindah: we’ll cross that bridge when we come to it), and, unsurprisingly, the final episode meshes moments of hilarity and sadness, as Grindah prioritises Kurupt’s first daytime rave over their wedding. There’s another crisis, too, for the already put-upon Steves, who has been bankrolling the station with his inheritance cash. Thankfully, even as we watch its much-loved protagonists sink to new lows, PJDN continues to soar right to the end.

People Just Do Nothing is on BBC3 now.