There's a real chance this one could actually happen.
Cristiano Ronaldo to Manchester City? Manchester City? Them lot? Unthinkable.
Or is it?
For some Manchester United fans, perhaps it is. You've heard the story a thousand times of Ronaldo moving to Old Trafford as a skinny 18-year-old - signed almost immediately after dazzling the first team players and Sir Alex Ferguson in a friendly against Sporting CP. Ronaldo had spent his evening tying John O'Shea into a pretzel and his deal was later tied up almost as quickly as one of his step-overs came and went.
Ronaldo's story was romantic; developing from a teenager with raw ability, bad teeth and a set of braces into an absolute unit obsessed with goals and trophies - all under the tutelage of the greatest manager of all time and his coaching staff.
They babysat him. They protected him after that wink at the 2006 World Cup and the abuse that came with it, and they channelled his energy and ability down a path to help Ronaldo become now, rightfully, one of the greatest footballers who has ever lived.
Or perhaps more accurately, the seventh best. No arguments please.
It's hard to comprehend for some fans to see a footballing hero, perhaps the one you grew up on, the figurehead of that all-conquering United side of 2007-2009 that were the first United team you really watched, join the local rivals. It's especially difficult considering how well run, successful, and well, rich, Manchester City are too.
This is a team infinitely more successful than United in the last decade and on a better footing, with a better squad, even now. Now it's "finish above City and you'll win the league". They used to say that about United.
Ronaldo moving to City may even impact some of United's players. Marcus Rashford has told stories of how Ronaldo inspired him as he used to stand on the seats at Old Trafford watching Ferguson's last great side tear the house down. How does he react to being a direct opponent in the Manchester derby on November 6? He'll remain professional, of course, but it'll be a little weird.
You can bet he wouldn't be the only one impacted, stirred by this happening in a sense, either. Though you should probably know that Mason Greenwood chose Lionel Messi's side in the age-old debate back in July.
Ronaldo to City would be a punch to the gut, a permanent stain on his United legacy, and perhaps the signal to stop the 'Viva Ronaldo' renditions around Old Trafford. At least temporarily.
But think about it. Is this really unthinkable, given all you know about Cristiano Ronaldo?
It's not. It's naive to think Ronaldo would turn down a transfer to a club who almost guarantee trophies every season. It's naive to think he'd move away from a club he's tried and failed to win the Champions League with in favour of joining a true, bonafide contender - especially when they're his only option. And it's naive to think he'd turn down, let alone push for, Manchester City out of loyalty to a club he left 12 years ago.
Ronaldo will continue to be obsessed with becoming the greatest player of all time until he retires, and he'll continue to use the best vehicle available to him to make that happen. This one isn't about money, nor club loyalty. It's about that final flourish in his career and winning as many trophies as he's able to at the top level before he packs it all in.
It'd sure be a heck of a brag for the retired Cristiano Ronaldo to say he was the man who helped them finally win the Champions League - and it'd be especially more impressive (in his eyes at least) to achieve that at the age of 37 or older. Imagine what he thinks that'd do for his case of becoming the greatest that ever lived.
Romance and loyalty in football is really difficult to find in football these days - the last 18 months has shown us that - and Ronaldo's footballing loyalties lie with nobody else, club or otherwise, but himself.
His six years at Old Trafford and the journey he went on to become a Ballon d'Or winner was magical. But United bred a win-at-all-costs beast who was fixated with getting to the top and staying there - and in simple terms City are a convenient option who have the capability of matching Ronaldo's ambitions.
This move may well happen prior to the transfer deadline at 11pm GMT on Tuesday, August 31, and it's time to strap in and realise it.
And hey, it's not that bad. At least we get to watch the final chapter of the Messi vs Ronaldo era played under a backdrop of oil money and sportswashing. It's the stuff dreams are made of.
If Ronaldo moves, they'll even meet each other for the umpteenth time in the Champions League group stages. A truly mouthwatering prospect.