Mickey Down and Konrad Kay, creators and writers of Industry, are in a rare position both perilous and blessed. Their show, about young Londoners working at the brutal end of the financial sector, is a sleeper hit. More and more people have learned to speak its singular language and now, with the arrival of season three, Industry has the floor. The spotlight burns.

Happily, its comeback episodes suggest this is the moment Down and Kay have been planning for all along. Industry returns with the pedal pressed down, with all the things that make it great intensified and sharpened. Goggling at it is more of a rush than ever.

The main characters now live together in a beautifully chic townhouse that they can never enjoy because everyone’s always in the middle of a work crisis – it’s like This Life without the cosy domesticity. Top of the stress league table is Yas (Marisa Abela), the heiress whose investment banking career cannot escape the shadow of her crooked plutocrat father. When she arrives for a crucial day on the trading floor at Pierpoint, her annoying colleague’s screen is showing a story about Yas’s family, via the MailOnline’s sidebar of shame.

Today is big because tomorrow is the IPO of Lumi, a green energy startup from the unique brain of the terrifically named Henry Muck (Kit Harington) – his surname being a signifier of the sort of privilege that gives people the confidence to play around with billions of pounds, and one letter different from the ultimate real-life example of the kind of pseudo-visionary modern high finance inexplicably reveres.

“I find I sleep deeper under my desk,” says Muck during an interview with an unimpressed Amol Rajan (playing himself), in which Muck tries to come across as a chilled-out entertainer. “That was me being humorous. We can cut that, it didn’t really land.”

A rich man’s futile quest to be funny and likable is one of a thousand contemporary observations Industry gets just right, but for the Pierpoint young ‘uns, convincing the market that Lumi is not a basket case is a serious business. Eric (Ken Leung), the boss of Yas and sensitive working-class conscience of the show Rob (Harry Lawtey), has his new senior management role to protect, a diktat from above to slim down his team by firing somebody, and a dodgy share price to inflate.

These are the necessary conditions for bedlam, and Industry does not hold back. Whether it’s a sudden death or an impromptu evening of cocaine-fuelled confessions in the office of a half-dressed lawyer, big events that could have been saved for a season finale are burned through in the first episode, at the end of which everything is on fire.

But none of it feels gratuitous: the show is tapped in to the absurdity of people playing a high-stakes game it is impossible to understand, because someone somewhere with more money than you is always tweaking the rules. That’s what has in the past made Industry temporarily impenetrable to newcomers. It’s all clear now, though, particularly the fact that if you zoom in closely enough, personal relationships and individual weaknesses are what matter. With everyone flailing in a complex web of secrets and hidden alliances, a phone call here or a well-managed argument there can mean professional life or death. Eric’s ultimate choice of who to sack is unpredictable until it becomes inevitable.

Meanwhile, Industry keeps nailing the details as well as the massive narrative beats. The scene where Yas is summoned to a meeting with Muck, to find the supposedly funky green innovator shirtless on the fives court of a Piccadilly gentleman’s club, is blackly hilarious – but by the end of episode two, Yas’s encounters with the toxic men in her life have become powerfully shocking.

Lifting the veil on the caprices of the super-wealthy is one way in which Industry is a post-Succession show; another lighter pleasure the two series share is the writers’ command of cultural flotsam and how people in the digital age interact. We are reacquainted with Harper (Myha’la) at her desk in her new dogsbody job at an ethical investment firm – you’ll need to hit pause to read the text she’s just received (“My Mubi account is about to expire and we still haven’t watched Decision to Leave – thoughts?”), and to see that she’s responding with a photo of herself with her hand down her knickers.

By Industry standards that’s pretty mild, but it’s earned the right to be the wildest drama on TV and it doesn’t pass the opportunity up. “My cortisol levels!” says Anna’s boss as her position on Lumi turns to ash. “I constantly feel like there’s an active shooter in the building.” Industry thrives on that danger.