"I owe it all to a stranger in the pub"

When he decided to leave Death in Paradise – where he played the linen-suited detective Humphrey Goodman – the BBC commissioned a spin-off that they agreed to film near his home, so he could be close to his family. Beyond Paradise – which swapped the Caribbean for Cornwall but retained the escapist charm – began last year and was watched by nearly nine million people in its first 30 days. “It was the BBC’s biggest new drama last year,” Marshall says over coffee in a hotel overlooking the Thames. “When I started seeing the ratings coming in, I was like, ‘OK, this is good… this is pretty good. To have the new show become a success was a real validation of the character and people’s love of it.”

Beyond Paradise depicts an England that vaguely resembles the real world but is prettier, with crimes solved in less than an hour. “It’s a show that harks back to a world that we still wish Britain was,” suggests Marshall, “a place where the world doesn’t take itself quite so seriously. The world has got too binary. It’s less nuanced. The world today takes itself so f***ing seriously.”

Marshall is 51 and grew up in a military family in Bath – his father was a navigator in the RAF during the Falklands conflict. “I had a very bucolic childhood in the south Cotswolds,” he says, “and then my folks sent me to boarding school.” He did well in his GCSEs but by the time he was meant to be studying for his A-levels he had discovered a passion for drama. “My school would put on six or seven plays a year and so I was very involved in that, to the detriment of my studies.”

How different might Marshall’s life have turned out, I wonder, if his parents hadn’t been able to send him to Wells Cathedral School in Somerset – where the current fee for boarders is £36,000 a year. Does he think he would have had the same opportunities to pursue his love of drama had he gone to his local comprehensive? “I wouldn’t have done,” he says honestly. “I’m sure of it because they don’t have the facilities to do that. I was given a great free reign with the facilities that were available to me at Wells.”

But that free reign meant he paid less attention to studying for his A-levels. “In my studies I was getting lazier and lazier,” he recalls. “I felt like I was some kind of rebel without a Porsche.” On the day of his maths A-level Marshall turned over the exam paper, realised he had no idea how to tackle it and instead spent his time drawing a picture of a calculator on the exam paper.

He left college and spent the following few years in a succession of unpromising jobs. “I worked in the laundrette of an abattoir where I would load aprons full of offal into industrial-sized washing machines,” he recalls. “It was appalling.” In the evenings Marshall would fax a heavily embellished CV to the casting director of the National Theatre, then call repeatedly, begging to be given a job, any job. “I had no other options,” he says, “so I had to be annoyingly cheeky.”

One evening Marshall, who was by then 24 and living back at home, was drinking in his local pub. He fell into conversation with a stranger. He told him about how he wanted to be an actor but that it wasn’t going well. The man told him he would give him a couple of numbers. One of the numbers was for a London agent called Barry Stacey. Marshall visited Stacey at his sixth-floor office on Charing Cross Road and it was through him that he secured an acting job for the play Deathtrap, which was being staged in Edinburgh. He spent two years learning his craft in Edinburgh before returning to London, where he was cast in a production of the First World War drama Journey’s End in a pub in Chelsea.

The theatrical entrepreneur Daniel Crawford decided to take it to his King’s Head Theatre in Islington and replaced all of the cast apart from Marshall. The play then transferred to the National Theatre – Journey’s End was Marshall’s start.

“From Journey’s End to me sitting on a plane in first class – next to Daryl Hannah – on my way to the Toronto Film Festival to promote my first lead in a movie [The Most Fertile Man in Ireland] was 18 months,” Marshall says. “I was cast in My Family the following year.” In other words, you owe your entire career to a stranger in a pub. “Pretty much,” he confirms. “I have no idea who he was but if he’s still around I’d like to buy him a drink.”

My Family, which launched on BBC1 in 2000, starred Marshall as Nick, the irresponsible son of Zoë Wanamaker and Robert Lindsay, and finally brought him fame. “We used to get 13 million viewers,” he says. “13 million! People will come up to me now and say, ‘I love that show because I watched it in my student digs’ or ‘I used to watch it with my folks and got to stay up late on a Friday’. It really brought people together. That’s hard to do.”

While filming My Family, Marshall also found time to make films – he was the “lovelorn” Colin Frissell in Love Actually and starred opposite Al Pacino in The Merchant of Venice. I read that Marshall had dinner with Pacino during filming – what was that like? “Bizarrely amazing,” he says. “He insisted upon us [cast and crew] going out for dinner with him every night.

There would be about 15 of us and he had this Corleone gravitas sitting at the head of the table. Years later he sent a telegram to my wedding. Wonderful man.”

Marshall was cast as DI Humphrey Goodman in Death in Paradise in 2014 and starred in the drama for four seasons. It was, at first, a dream gig – spending five months in the Caribbean (the show is filmed in Guadeloupe) – but Marshall eventually quit. “I had young kids [he has two children with his wife Hannah] and I wasn’t seeing much of them,” he explains. “I didn’t really want to spend five months of the year not seeing them or only seeing them one week out of 20.”

He left in 2017 and that, viewers assumed, was the end of it. But, as his old friend Al Pacino might have said, just when he thought he was out they pulled him back in. The team behind Death in Paradise suggested reviving the character but relocating him closer to home. Marshall was enthused enough to reprise Goodman. Beyond Paradise is set in the fictional Devon town of Shipton Abbott and filmed in both Devon and Cornwall. “It was always going to be in the South West,” he says, “because that’s where I’m from.”

Marshall’s enthusiasm for Beyond Paradise is palpable and it’s undoubtedly popular with viewers, but I wonder if it irks him that so many of the shows he has appeared in are more popular with audiences than critics. “You always want critics to like your work,” he says. “I have a theory – not a theory, actually, it’s a fact – that to make a show like Death in Paradise or Beyond Paradise, that has a broad demographic, that you can sit down and watch with your kids, that bonds all family members in the room, is incredibly hard to do. And to have people scorn it… I’m fine with it now but it bothered me a bit in the past. These shows are hard to make and they bring people together – that’s got to be lauded a little bit, right?”

Regardless of what the critics think, the success of Beyond Paradise means more series are inevitable. Meanwhile, Marshall is happy staying at home and spending time with his wife and children. “To be in a position where you can earn a living doing what you love is good enough,” he says, “but to then be in a position to choose how you earn that living – that’s nirvana.” Nirvana is certainly one word that captures Marshall’s peaceful happiness – another is paradise.

Beyond Paradise Friday 8.00pm BBC1