It's the transfer link that simply refuses to go away despite the ever-changing landscape of the two clubs involved.
Odsonne Edouard is likely to leave Celtic this summer - that we know.
But the name of Arsenal consistently appears among his potential landing spots for a move away from Parkhead.
When he was first linked, Arsenal had a hungry young manager and were making moves in the transfer market that seemed destined to fire them into the top four and potentially beyond. Celtic, of course, were gunning for 10 In A Row.
Fast forward through the autumn, winter and up to mid-spring.
Both clubs have endured torrid campaigns that yet could still finish on a wave of optimism should the Gunners land the Europa League and Celtic scoop the Scottish Cup before appointing a boss that unites a hopeful fanbase.
The more things change the more they stay the same and this week Edouard has once again been linked with a North London switch.
Here are the threads of intrigue that show why this rumour refuses to budge.
Summer links
The rumours first cropped up during last summer's monster window that ran all the way until October 5.
Among reported interest from Brendan Rodgers' Leicester City and Aston Villa, Arsenal were said to be weighing up an offer.
But it seems like at the point they were happy to bide their time.
The Athletic's David Ornstein is the top dog when it comes to transfer ins and outs at the Emirates.
And his summary of the window claimed that Mikel Arteta, while reportedly keen, did not make any contact.
With Pierre-Emerick Aubameyang's bumper new contract there seemed little reason to go out and sign another striker, but now the landscape has shifted.
Shake up at the Emirates
It's a rumour with a degree of longevity about it and that Edouard is again being linked to the Emirates is no surprise given the situation in the Gunners attack.
Manager Mikel Arteta seems destined to shake things up and Alexandre Lacazette is on his way out of the club according to reports.
Aubameyang has been a disappointment since signing a new contract at the club and will be 34 by the time his deal comes to an end.
It looks like highly-rated American teen Folarin Balogun is set to sign a bumper four-year deal, however another youngster in Eddie Nketiah could be sold this summer.
Edouard is still only 23, as hard as that is to believe, and he would represent a superior option up front for years to come with Aubameyang in the twilight of his playing days.
Renewed interest
That leads us to the rumour mill churning away once more ahead of this summer.
On Monday The Telegraph reported that Arsenal are hoping to overtake Leicester in the battle to land Edouard this summer.
With Edouard only having one year left to run on his stay in Glasgow, it's claimed Celtic are prepared to entertain offers of around £15m and up - rather than the £30m-plus they might have hoped for previously.
Selling Lacazette is identified as the easiest way for Arteta to generate those funds but that could depend on Arsenal's ability to secure Champions League football next season.
They have been a major disappointment in the Premier League and winning the Europa League remains their last shot at dining at Europe's elite table.
The agent switch and Tierney connection
Edouard changed his representatives at the turn of the year, a move that had fans bracing for movement no more than a week after the winter window had opened.
He's now in the hands of London firm ICM Stellar Sports.
That agency is the same one that helped bring Kieran Tierney down the same path from Parkhead to the Emirates in August 2019.
A deal in that window didn't come to fruition but it could signal a shift in his personal aims and a preferred destination.
Stellar represent some of the Premier League's other top talents including Tottenham's Gareth Bale and Aston Villa playmaker Jack Grealish.
Henry buttering up
Okay, it was in fact revealed by former Rangers hero Ally McCoist.
But it's interesting that club legend Thierry Henry is keeping a close eye on Edouard's career.
He told the Ibrox goal machine while the pair were on Premier League punditry duty that he's a massive fan of the French Under-21 internationalist.
Henry will still no doubt have connections in North London and could easily have had a few conversations with those in high places.
McCoist said: "I spoke to Thierry Henry at the Liverpool vs Leicester City game and he really rates Edouard.
"He was saying in France in particular (Edouard is admired) and he personally really, really thinks he's got a chance of going right to the top."
