After more than a decade of posturing and power struggles - a soap opera of warring promoters, shifting managers, fractured television deals and failed negotiations - it has finally come down to this.
The biggest fight in British boxing history - Tyson Fury versus Anthony Joshua - hangs on one final two-day stretch.
On Friday, Fury, 37, fights Mariusz Wach in the unlikely surroundings of Pattaya, Thailand. There is no broadcaster, only a modest crowd expected and a 46-year-old opponent.
The following evening, almost 4,000 miles away in Jeddah, Saudi Arabia, Joshua returns against Kristian Prenga - an Albanian knockout artist whom even the most hardened boxing fans would struggle to pick out of a line-up.
If all goes to plan, Fury will leave Thailand within hours of beating Wach, board a private jet and fly to Saudi Arabia, where he is expected to climb through the ropes and finally stand face-to-face with Joshua.
The contracts are signed but, especially in boxing, the ink is never truly dry until the opening bell rings.
Why Joshua needed this warm-up fight
Fury and Joshua, 36, have defined British heavyweight boxing for more than a decade without ever sharing a professional ring.
Yet they arrive at this moment for very different reasons. For Joshua, it is about far more than shaking off ring rust.
The two-time world champion has not fought since surviving the car crash in Nigeria last December that claimed the lives of close friends Sina Ghami and Latif "Latz" Ayodele.
Joshua has spoken about the emotional toll of the tragedy. Promoter Eddie Hearn believes boxing has "saved" Joshua - just as it did when he first took up the sport as a troubled 19-year-old searching for direction.
"When you come off an incident like that and an accident like that, I guess people say, 'Will you ever be the same?' Certainly everything he's shown in training camp, after he went through all the near-impossible work to get himself in that position, shows that he is," Hearn told BBC Sport.
"The questions that you ask yourself, the moments where your head hits the pillow at night and it's just you in your room, what's going on inside between those two ears?"
There was also the physical recovery.
"In the early stages, just a slight movement in bed would be excruciating pain," Hearn said.
"To getting back on the bike and doing two hours' cycling when he couldn't move his upper body, and going through the physio sessions, that was an incredible journey."
Fury's warm-up about publicity, not preparation
Fury, who briefly retired after back-to-back defeats by Oleksandr Usyk, already had the comeback fight many felt he needed when comfortably outpointing Arslanbek Makhmudov in April.
BBC boxing pundit Steve Bunce is not convinced another outing was necessary.
"The fight against Makhmudov was perfect, it was the dream fight for a fighter after a long break," Bunce says.
"You could see he wasn't bothered about the stoppage, he just needed those priceless rounds. But this fight against Wach is one he will not lose under any circumstances. It's ceremonial."
Fury's trip to Thailand appears to be as much about publicity as preparation.
The cameras for the third season of his Netflix documentary, 'At Home with the Furys' will be rolling at ringside with exclusive access. No other broadcaster will be present.
Will they both win and is Fury-AJ at risk?
It would rank among the biggest upsets in heavyweight history if Fury lost to a man who turns 47 this year and has lost seven of his past 10 fights.
"Fury should dominate but the biggest risk for me is that he looks awful," Bunce says.
"Also, Tyson might find out that he has lost something and senses some flaws in himself."
There is a fraction more jeopardy for Joshua. Prenga is largely an unknown quantity to the wider public, but his record demands respect: 20 wins, 20 knockouts and one defeat.
"This fight is designed to be competitive, but not too competitive," Hearn says.
"He's never boxed at AJ's level, but until you fight at that level, you actually don't know if you're good enough. But he's decent, he's game and he's dangerous."
The greater threat to the Fury-AJ super-fight is injury.
"Tyson is too smart and clever and I think Wach won't be using his elbows or head. There will be some sort of gentleman's agreement," Bunce adds.
"He could injure his arm or leg. At Tyson's age, with hard training camps, that can happen. It could also happen to Joshua."
Will Fury take a private jet to Jeddah? Where will Fury-AJ land?
If both men emerge unscathed, attention will quickly turn to Jeddah. The hope is that Fury will travel straight from Thailand and join Joshua in the ring for an official announcement.
"Perhaps Fury will get on a private jet and arrive in Jeddah - give it a bit of drama in the style of WWE," Bunce said.
"But if they both win, you have to announce it right then. You can't let it slip."
Remarkably, the two have only ever shared a ring once before - a semi-mythical sparring session back in 2010 when Fury was a 21-year-old prospect with an undefeated professional record and Joshua was a raw 20-year-old amateur.
Hearn is a little less certain Fury will make the journey to Saudi Arabia.
"We hope, now that the contracts are signed, we'll see him on Saturday," Hearn said.
"I would suggest most people would get on a plane, but he is Tyson Fury."
Saudi Arabia powerbroker Turki Alalshikh, a key figure in bringing together Fury v Joshua, has said that for the fight to happen on British soil, it would require a middle-of-the-night start time at Wembley Stadium to cater for prime-time American audiences on Netflix.
Such a plan would require extending Wembley's usual 11pm curfew, although sources close to London Mayor Sadiq Khan indicated the city would be willing to help make it happen.
Industry whispers point towards Las Vegas or New York, while Hearn says Joshua's contract stipulates the fight must happen in the UK - but he has not ruled out a move to America.
The prospect of the biggest British fight in history taking place thousands of miles away is a difficult one for many UK fans to accept.
Whatever unfolds across these extraordinary coming hours, we are about to find out whether the biggest fight in British boxing history is going to be a reality or destined to remain the sport's greatest what-if.
BBC