Captain Gibson Ferrier Steven lived in Castle Terrace in Berwick, the border town where the former Rangers, Everton and England midfielder grew up.

When retired archeologist Lindsay Allason-Jones moved into the house, she happened upon an old reinforced air-raid shelter in the garden.

Archive research found that the Wilmot Fortress Shelter had actually been a listening post used to monitor transmissions and gather critical data on German warships and submarines in the North Sea during both World Wars.

The intelligence was then fed back to Bletchley Park, the Allied code-breaking hub immortalised in the movies Enigma and the Imitation Game.

One of Britain’s wartime Voluntary Interceptors, the mysterious Captain Steven, passed away in 1953. The Official Secrets Act always prevented him from telling anyone about his role in the classified network which helped to sink the Bismarck and the pocket battleship Scharnhorst.

Thrust into his very own episode of Who Do You Think You Are?, Trevor’s life could have propped up the family tree all by itself.

Part of the mythical Everton team which won two English titles, an FA Cup and a European Cup-Winners’ Cup, he turned down Manchester United to move to Rangers when teams down south were banned from UEFA competitions and arrived at Ibrox to find more English talent than the Edinburgh Festival.

Seven Scottish league titles and three League Cups followed over two spells, and he squeezed in a Ligue 1 crown at Marseille during a brief adventure in France.

His was a story almost as improbable as that of the mysterious grandfather who had been a war hero. As far-fetched as Maurice Johnston signing for Rangers 10 days after Steven’s move from Everton.

“One of my grandfathers was a policeman in Ecclefechan, near Lockerbie,” he tells The Herald. “The other was the subject of the book that came out last year, The Spy in The Berwick Garden, which told of him being a radio communications expert and a spy who basically worked for military intelligence in the First and Second World Wars.”

Born in Berwick-Upon-Tweed to English parents, Steven always nursed some confusion over his identity. By the time he joined Rangers in 1989, he was already an England internationalist, going on to play 36 times for the Three Lions and appearing in two World Cups.

Yet every time he opened his passport, his full name read Trevor McGregor Steven.

“By birth I am 100-per-cent English, but if you look beyond that it all starts to look more Scottish-looking. More nuanced.

“I sold programmes for Berwick Rangers, and there were always 347 people there unless Celtic or Rangers came to town. I actually lived a mile inside England. When you are little, a mile is quite far, but I could literally see Scotland from my bedroom window.”

Trevor Steven in action for Rangers (Image: Colorsport / Shutterstock)

An identity crisis of a different kind loomed when the football stopped in the aftermath of Rangers reaching nine-in-a-row in 1997. Walter Smith’s knackered team was running out of road by then, and the same could be said of Steven’s injury-plagued career. A vascular issue in his leg became irreparable. At the age of 33, his time was up.

“How did I cope with that? I didn’t really. I was divorced in two years. My routine was gone, and I was living at home with three kids every minute of every day after 20 years of basically travelling the world.

“That was it stopped. And that took a lot of getting used to. I don’t know that any footballers cope with that well, and I certainly didn’t.

“Once I stopped playing, I stopped having a purpose. You trade off being a footballer for a while, and then you become irrelevant. You become lost in a sea of retired footballers.”

Steven never really had the coaching bug. Despite dabbling in bits and bobs of media work, he never felt like a “football person” and had no driving desire to stay in the game. Bored with the sport, he felt there had to be more to life and went in search of fulfilment and purpose. There was a payroll business; he owned some shoe shops and fell into life as a football agent.

“I fell out of love with that when my business partner Blair Morgan retired,” he admits now. “I was only doing that to keep the wolf away from the door. I didn’t enjoy it at all.”

Eventually he moved to Dubai for a fresh start and lived in the expat Emirates stronghold for the best part of a decade.

By the time he hit 55, even the sun had lost its appeal. He began to display some of the symptoms of a man grappling with a mid-life crisis.

“I was pretty well washed-up. I had no opportunities or transferable skills. My stock value was never in the UAE. My value, if you like, was in the UK.

“Every year, fresher, newer and more relevant people came on the scene. I was getting pretty depressed at that point about not having an answer.”

The future had looked so much brighter 30 years earlier, in the summer of 1989, when he was slap bang in the middle of a tug-of-war between two of the heavyweights of British football.

In one corner stood Alex Ferguson. In the other stood Graeme Souness, the Rangers boss who had been winking in his direction for the best part of two years. In a sign of the times, Rangers came in with more money.

“English football had been weakened by the ban from Europe. That was a key thing for me, but the way I am built I didn’t want to stay in England anyway.

“I had a brilliant time at Everton, and we had won everything that we could, and I was still only 25.”

His last game for the Toffees was the 1989 FA Cup final defeat to city rivals Liverpool and after 48 goals in 210 appearances he did the one thing few had the guts to do. He said no to Fergie.

Gordon Strachan was leaving Old Trafford, and Steven was earmarked as the Scot’s natural replacement on the right of midfield.

“But I didn’t want to go back and play against Everton wearing another shirt,” he reflects. “So I went up to Rangers and Gary Stevens, my old Everton mate, was already there. We were thick as thieves. Terry Butcher and Chris Woods and Ray Wilkins and Trevor Francis were there as well, and I just loved Iain Durrant. He was one of the best players I had seen at that time in the game.”

There was an attraction to returning north, closer to his Berwick roots, where his family could watch him play in the European Cup in front of a full stadium of 50,000. Initial excitement over the arrival of another England internationalist at Ibrox was quickly overshadowed by a rare and exotic arrival 10 days later. Rangers had finally signed a Catholic.

“Maurice Johnston came in, and I was well and truly parked in the headlines. But that was great for me. In those days things were happening at Rangers all the time.

“You would never know what was coming next. There would be a Graeme Roberts situation or a Terry Butcher situation or a new big name coming in. It was just exciting times, and I loved it. I must have, because I went there twice.”

Ah, yes. A sojourn in Marseille came in 1991, weeks after the French giants lost the European Cup final to a gifted Red Star Belgrade team. Rangers didn’t want to sell but succumbed to a tempting record fee of £5.5 million.

Steven had always fancied a move abroad and a bulging salary helped. His team-mates were Jean Pierre Papin and Chris Waddell, and the sun shone until the day he was surplus to requirements. He returned to Glasgow and won another haul of trophies, ending his career as Rangers made it to nine in a row under Walter Smith.

He searched, but never quite found, a new direction until he agreed to take part in a film recalling the story of Howard Kendall’s title-winning Everton team of 1985.

Howard’s Way was part-funded by an Evertonian by the name of Phil Brown, owner of a business called Causeway Technologies. Later, Brown called Steven in the Middle East after hearing a story on Five Live about construction workers taking their own lives. A fortnight later, the former midfielder returned to England as Causeway’s new ambassador for mental health.

Steve Trevor (Image: Chris Squire)

With a spring in his step, he donned a high-viz jacket, a pair of boots and a hard hat and started touring building sites to share his own mental-health problems with construction workers and to quiz them on theirs.

“I knew what the experience of being a footballer was like. The macho environment of the dressing room,” Steven says. “If you opened a little window of weakness, you would be a laughing stock. You would be picked on and isolated or maybe bullied.

“For over 25s it’s not so bad, but for younger guys of 16 or 17 joining a football club, it’s brutal. These days they are safeguarded and protected, but back in my day it was every man for himself. Survival of the fittest, and many a talent disappeared because they couldn’t cope. The macho side of the dressing room seemed to me to resemble the workplace in construction.”

A survey of 1,500 construction workers found that 85 per cent followed a football team of some description, and Mindflow was launched in March last year in the National Football Museum in Manchester.

Endorsed by the likes of Ally McCoist, ex-players such as Clayton Blackmore and Paul Stewart go into building sites to remind workers exposed to wind, rain and uncertain prospects that it is okay to feel vulnerable.

On the Mindflow website charter, 10 core principles are lined up in a 4-3-3 formation. Measurable Performance leads the line in the No.9 jersey while Fairness and Awareness form a partnership in the centre of the field.

Now 63, Steven draws more headlines in the pages of Construction News than he ever did in the British tabloids at the peak of a decorated football career. Evertonian Andy Burnham provided encouragement until a recent change of job made him a little harder to reach.

“What I am trying to do with the Mindflow football ambassadors is find local heroes,” says Steven. “Who is the local Dundee United hero? Or the local Elgin City legend? They need to be relatable.

“It’s cathartic for the footballer as well. Because when the audience leaves the room, they give them a standing ovation and a bit of a hug.

“I’ll speak to the ex-footballers after sessions, and they’ll say, ‘It was good today, I had a couple of young lads reach out…’

“And that gives me such a lift, you know. This is my passion now. I am doing this because I think I can make a change. I can make a difference.”