Inside the confines of a square Zoom window, his visage softened slightly by the pixelation of a laptop screen, a tracksuited Callum Simpson is sat in front of a white wall. Sometimes communicating this way can inhibit the emotions behind a conversation, but as the boxer remembers his late sister Lily-Rae, his grief, love and hope are visible in subtleties – the twitch of a smile, the furrow of a brow, the pause in a sentence.

“Everyone handles grief differently,” Simpson tells The Independent. “Losing my baby sister, Lily-Rae… she was my biggest fan. Yesterday actually, it came up on my Facebook memories that – seven years ago – there was a picture of us together just after I’d won a fight. I got a little tear in my eye.”

Simpson and his family lost Lily-Rae last August. She was just 19 when she passed away following a quad-bike accident, with the tragedy slicing through the elation of her brother’s British super-middleweight title win that same month. For Simpson, grief and success are entwined like boxers in a clinch.

“You almost feel guilty when you’re having fight nights and all the family comes together,” the 29-year-old says, “because she’s not here to enjoy it. But the comfort I do take is that she’s looking down on me, she’s with me. I always try and give a tribute on my fight kit, I always try and talk about her.

“The last photos I’ve got with her are from when I won the British title. I’m looking now at my cabinet, a picture of me and her just looking happy and seeing how proud of me she was. I mean, she’ll still be proud now and I want to continue to make her proud.

“But it’s still very, very hard. When people say, ‘I’m not gonna go a day without thinking about that person,’ I always used to think: ‘Oh, that’s an exaggeration.’ But I don’t go a day without thinking about Lily. And I know that if Lily was here, and if it was me that passed away, she’d still be having a good time. She wants me to have a good time as well. And if anything was to happen to me, I’d want my family to have a good time and to be happy that I was in their life. I’m happy that Lily was in my life as well.”

Simpson has discovered a remarkable resilience in the face of such desolation, with 2025 marking his second-most active year in the ring. When he boxes Troy Williamson on Saturday, it will be Simpson’s fourth outing of the year. Many, surely, could not comprehend this ability to endure. For the unbeaten Simpson, though, perhaps it has been essential.

His fight with Williamson sees him headline Leeds Arena as he fights there for the first time since his second bout, way back in 2019. “I can remember that night very well,” says Simpson. “I was in camp with Josh Warrington, watching how he prepared for a championship fight, and I was training for my second four-rounder. So obviously I was doing the circuits with him, but doing like a quarter of the work, and thinking, ‘I’m never going to be fit like him!’ Now I’m doing the circuits he was doing, and I might be beating him on a few times… But in terms of the actual fight night, I think I was on about 4pm – half my family and friends didn’t get to watch me, because they’d just opened the doors. I’ve got no footage from the fight. Troy was actually on that card as well.”

This weekend’s main event also confirms Simpson as one of Britain’s most-reliable headliners in recent years; it is impossible to overlook his two fights at Oakwell in particular, as the super-middleweight topped the bill at the home of his beloved Barnsley FC. While the first of those fights came last August, shortly before Lily-Rae’s passing, the latter was his most-recent outing: a stoppage of Ivan Zucco in June.

“Never in my wildest dreams did I imagine that I’d be fighting at Oakwell,” Simpson confesses. “It never once came to my mind, never. It just… it seemed… it would have been something so out of reach that I never…” He still looks bewildered now. “It’s more than a dream come true,” he says, finally finding the words.

“It was only the year before when I was watching Chris Billam-Smith [at Bournemouth’s stadium] with one of the business partners at [promotional company] Boxxer. We were looking around, and he was saying: ‘This will be you next year.’ I was like: ‘Oh, yeah, imagine.’ He looked at me and said: ‘No, this will be you next year.’”

It is little wonder that Simpson is somewhat disbelieving, given how far he has come – and given that he is, in his own words, “the biggest armchair fan, casual boxing fan that you can find”.

“I’ve always done my own tickets,” he adds, before reflecting on his last fight at Leeds Arena: “Obviously, back then it was a few hundred, but I’d always hand-deliver tickets and meet people individually; now I do ticket-collection days, doing a few thousand. I was working full-time back then as well, 45 hours a week as a store manager. If that was me now, I’d be working Christmas Eve, Christmas, Boxing Day, New Year’s Eve, New Year’s Day. That’s real work; this is so easy.”

It was during those days in retail work that Simpson met Sheffield boxing hero Kell Brook, is one of Simpson’s inspirations – but not for the reason you might expect. As Simpson says, he is a “casual” boxing fan, and he has always drawn inspiration from a person’s “character” rather than more obvious achievements.

“There was a lad in my gym called Jack Churchill,” Simpson recalls, as he begins to prove his point. “He’s not a pro anymore, I think he had like five fights, but just seeing his work ethic and how he was as a person, he was a big role-model to me. I don’t look at what people have achieved, but how they treat people, their character, how they navigate life.”

That brings us back to Brook. “I used to work in the shop that used to sponsor Kell. He would come in for free shoes, so I used to lace them up for him. He was just a normal person – always polite, well mannered, normal. When you see someone on TV or in the ring, you think they’re some superstar and you build them up to be something they’re not. Like, he is special, but there was no reason I couldn’t do what he was doing.

“And I always say how proud I am to be from Barnsley and Yorkshire, especially when I go into schools or colleges or do talks in my community. I let them know that someone that’s walked the same streets as them, gone to the same shops as them to get a bargain, walked the same corridors at school, can go on to achieve their dreams.”

Last year, Simpson’s dream dissolved amid the nightmarish reality of Lily-Rae’s passing. But now, day by day and fight by fight, he is learning to dream again.

Callum Simpson vs Troy Williamson is available to watch live and free-to-air on Saturday 20 December, on BBC Three and BBC iPlayer.