The transfer window hasn't even been open for a week, yet it's already been a tumultuous summer for Borussia Dortmund.
The Bundesliga side have effectively been gutted; their best defender, central midfielder and attacking midfielder having been sold in the form of captain Mats Hummels, Ilkay Gundogan and Henrikh Mkhitaryan, respectively.
And now the question arises: Why is it that Dortmund cannot keep their stars? The answer is a complicated one.
There are many reasons why players should enjoy playing for Dortmund and see it as more than just a stepping stone. The club have incredible support on a regular basis: Their average attendance has been Europe's best for years, with their 2015-16 average standing at a whopping 81,178, according to Statista.
They even drew 65,190 to their home match against Austrian side Wolfsberger in the Europa League third qualifying round last August, per UEFA, shattering the record attendance for that level of competition by over 10,000.
When it comes to passion and loyalty, Dortmund fans are truly superlative. Their stadium, Signal Iduna Park, possesses perhaps the most impressive atmosphere in all of world football.
Dortmund also have an outstanding coach in Thomas Tuchel. The former Mainz trainer took a team that seemed to have lost its way shortly before his arrival and turned it into a well-oiled machine.
BVB finished seventh in the 2014-15 Bundesliga season, a mile behind winners Bayern Munich, yet a year later, they stood second with the league's best-ever points haul (78) for runners-up. It would have been enough points to win the title in nearly any other year.
Tuchel's players almost unanimously rave about what the coach brings to the table. He took a flop in Mkhitaryan and turned him into one of the world's most coveted attacking midfielders. Julian Weigl came to Dortmund as a teenager with no Bundesliga experience a year ago and has since become a senior Germany international.
A year after spending much of the season flirting with relegation, Dortmund are now playing attractive, cultured football in a way Jurgen Klopp's two-time Bundesliga winners never could. It looks to be sustainable and the players love it.
Yet they keep leaving, and now it's faster and faster. After BVB won the Bundesliga in 2011, Nuri Sahin left. The following year it was Shinji Kagawa. Then Mario Gotze in 2013, followed by Robert Lewandowski a year later. The summer of 2015 was a rare year in which Dortmund didn't sell a key player, but now Hummels, Gundogan and Mkhitaryan are gone.
In Gundogan's case, a sale was a long time coming. He might have left in 2014, but injuries saw minimal interest in him that summer and in 2015, and each year he penned bare minimum one-year extensions with BVB. Having been fit for most of the 2015-16 campaign and impressed enough to attract attention from Manchester City and Pep Guardiola, he jumped ship.
Gundogan's decision brought back memories of Klopp's reaction to Gotze joining Bayern. Per Deutsche Welle, the trainer said he couldn't "shrink 15 centimeters or start speaking Spanish" to match Guardiola. Similarly, as as great as Tuchel is, he just isn't Guardiola and won't have that allure.
In Mkhitaryan's case, finances are likely a big factor. Bild (h/t Goal) reported on Monday that the Armenia international will receive €12.5 million per year for his four-year contract, plus an €8 million sign-on bonus.
For a club that earned approximately €200 million less than Bayern and Paris Saint-Germain, €240 million less than Manchester United, and half or less than what Barcelona and Real Madrid earned, according to Deloitte's most recent Football Money League, there was no chance to compete.
BVB had to sell, and, sadly, they will likely have to continue to do so in the future as the mega-rich flex their financial muscle.
Hummels' decision has largely been painted as one based on the heart, with Bild (h/t ESPN's Stephan Uersfeld) reporting that Bayern and Dortmund both offered him a €10 million annual wage. In that case, it wasn't an issue of money.
The defender has, however, told Bild Am Sonntag (h/t ESPN's Stefan Buczko): "I realize in every year I don't win a title, I'm closer to retiring. The Champions League is a target for me in any case. I want to win this title."
A few Bundesliga titles probably wouldn't hurt either, but the fact is that Dortmund are not competitive in the German top flight. They did nearly everything right in 2015-16, yet still finished well behind Bayern. And in the three years prior, there was no competition.
Hummels' revelation was a marked contrast to him telling Welt am Sonntag (h/t Goal) in 2014 that he'd prefer to win the Champions League once with Dortmund rather than six times with another club, and that he didn't necessarily need to play for a bigger side.
Via his Twitter account, Buczko recently cited a WAZ interview in which Hummels claimed he knew that Gundogan and Mkhitaryan had plans of leaving before making his decision to move to Munich.
The Hummels story plays into the narrative that "Echte Liebe" (BVB's motto of "true love") is dead, something that appeared to go when Gotze left the club three years ago. After pledging his future to the club of his youth, the decision to leave as the team reached their peak and progressed to the Champions League final sent shock waves around Dortmund.
Although they'd had generally good results in keeping their key players prior to 2013 (Sahin and Kagawa had gone, but they had fended off interest in the vast majority of their stars), things started to fall apart for BVB with Gotze's sale. And even though Tuchel did well to resurrect the Dortmund team last season, it's clear that "Echte Liebe" remains a thing of the past.
Dortmund don't have the prestige of Real Madrid, and Tuchel is not as attractive to play for as Guardiola. They can't match the wages other clubs will offer, and when they can, their negotiating position is still weaker due to the fact that they can't offer the title chances that bigger sides can.
And so, their players continue to leave. Some, such as Hummels, Gotze and Lewandowski, head to Bayern with guaranteed domestic success and sky-high wages. Others, like Mkhitaryan and Gundogan this year, move to the more competitive and cash-loaded Premier League.
With their decisions, the players by and large have decided that these factors are better than any fairytale "Echte Liebe" story Dortmund could offer.