Isak, born in the Stockholm suburb Solna to Eritrean parents, came through the youth system at AIK, the 12-time Swedish champions. He began playing at the age of six and just a decade on he was a fully-fledged first team player, scoring on his debut in a cup tie at Tenhults IF. It was lower-league opposition but the rangy forward stood out, and not just because of his age - he became the club's youngest-ever goalscorer that night in February 2016 when he was just 16.
In action for Sweden against Slovakia in the 2017 friendly that brought Isak's first international goal
His rise was rapid at the Gnaget and further records fell. Isak became their youngest scorer in the Allsvenskan, Sweden's top tier, a few months later and continued to deliver as a boy in men's football. He wasn't too far from home, either - the Friends Arena, where AIK play their home games, was opened in Solna when Isak was just 13.
A first professional contract was signed later that year and, in January 2017, at the age of 17, he became a full international. After being named in the Sweden squad for friendlies with the Ivory Coast and Slovakia, a debut arrived against the former and a first goal arrived just 19 minutes into the game against the latter. Another record broken; the youngest goalscorer for the Sweden national side, at 17 years of age.
Isak, right, with Pierre-Emerick Aubameyang and Ousmane Dembele at Dortmund
Interest in the teenager was high. Real Madrid were heavily linked but later that month, just a few weeks after first his goalscoring international turn, he moved to Borussia Dortmund, a club with a record of developing precocious young talents.
It was a move he felt ready to make. "I didn't hesitate to leave Sweden, it was just deciding where," Isak said in that Independent interview, looking back on a move that didn't quite take off. "In football, you never know when the next chance is going to come, and so you take it. Obviously, as a young player, you need time on the pitch. If you're not getting that, all you can do is train harder. That's what I did, I stayed later, I trained on my own as well. I knew my chance would come, even if it wasn't there, I knew it would come at another club and I wanted to be ready."
Rolling home a penalty against Ajax during his prolific loan spell at Willem II
His time at Signal Iduna Park was stop-start. Bundesliga appearances were hard to come by in a transitional Dortmund side but in January 2019 he joined Willem II on loan until the end of the 2018/19 campaign. The next few months brought a flurry of goals, and yet more firsts. Isak, who ended up with 14 goals in 18 games at the Superkruiken, became the first player score a hat-trick of penalties in an Eredivisie match against Fortuna Sittard, as well as the first non-Dutch player to bag 12 in his first 12 appearances in the Netherlands' top flight.
It was the season Isak regards as "the most important of my career" and it led to another move, this time to Real Sociedad, that summer. Nine goals in his first campaign in LaLiga - along with a Copa de Rey winner's medal - represented a promising haul but 17 in 34 outings in 2020/21 confirmed his place among Europe's most coveted attacking players. There were four outings and a couple of assists at the delayed EURO 2020 that summer, too, his first major international tournament. With Zlatan Ibrahimovic in the twilight of his career, Isak is likely shoulder his country's attacking burden for years to come.
Isak scoring his 44th and final goal for Real Sociedad against Barcelona last week
He arrives at St. James' Park barely a week on for scoring a terrific chip against Barcelona last week - his 44th and final strike in Spain. It was a memorable way to sign off after 132 games for Los Txuri-Urdin but now he is a Premier League player, fulfilling an ambition he has long held.
Isak is a young man with his best years still ahead of him. Heading to St. James' Park, he feels, was a choice that just felt right. "There's a lot of parts that needs to be in place to make a big decision like this," he told NUFC TV. "But I think a big reason is the big project that this club has going. I've seen the way they play - it's very attractive football - and not least the amazing fans as you can see. (They're) very passionate fans, and you can feel just by being here that this city breathes Newcastle. I'm very happy to be here."
