Pirate radio station Kurupt FM is back - hurrah – but it has a rival – hiss. In the first episode of the new series, best MC in the galaxy Grindah (Allan Mustafa) has grown his hair, got hooked on coke like a Brentford Tony Montana and is paranoid about new local pirates on the block Kold FM muscling in on his patch. He cannot contain his anger over their spelling: “We invented the K,” he tells his crew before getting even more paranoid and deciding to move their base.

While it still has the mockumentary echoes of The Office, PJDN has really grown in confidence over each series and this fourth run looks stronger than ever. Grindah is losing it big-style and has given up changing his clothes. He has also broken up with his girlfriend Miche (Lily Brazier), who has modelling aspirations and thinks she is going to be the new Kate Moss, or maybe Jordan, when a local snapper wants to put her pictures on his website.

Meanwhile Brent-ish entrepreneur Chabuddy G’s (Asim Chaudhry) business doesn’t seem to be doing as well as he claims. While he insists he hasn’t closed down he seems to be operating from – and living in – a transit van. But he means well - he might try to chat up the new mums shopping for babyn accessories, but with the others, including Steve Stamp as dopey Steves and Hugo Chegwin as almost as dopey Kevin "DJ Beats" Bates, he is there to stage an intervention for Grindah. Or, as Chabuddy keeps calling it, an “interwention.”

Will Grindah clean up? Will Kurupt FM be able to retain the support of their West London massive? Or given their listening figures should that be “smallive”? Stay tuned for the Kold War, bruv.

Watch on iPlayer here or on BBC One on Saturday at 11.50pm.