When Erling Haaland takes the field for Manchester City on Wednesday in Munich, the Norwegian will face the club who tried to sell the farm to buy him but failed.
Bayern's late first-leg capitulation in Manchester means the six-time winners need to overcome a 3-0 deficit to make it through to the semis.
Not only must Bayern do so against Europe's form team, but they need to somehow find the goals that the toothless front-line have lacked in 2023.
Midway through the second half at the Etihad, Bayern, 1-0 down after a Rodri wonder goal, were dominating possession and had carved out several chances, but failed to put any away.
Then, in a six-minute period, the brutally efficient Haaland showed what Bayern were missing up front, setting up a goal and then scoring another to put City on course for the semi-finals.
While Haaland's flurry likely sunk Bayern's Champions League hopes then and there, the seeds for their struggles were planted late last season, when the German champions tried and failed to sign the Norwegian.
Bayern sporting director Hasan Salihamidzic was not alone in his desire to sign Haaland, but his open courting of the Norwegian put noses out of joint, particularly that of star striker Robert Lewandowski.
In 2021, a clip emerged of Salihamidzic on the sidelines of a Bayern-Dortmund clash, speaking with an assistant coach after Haaland scored twice in seven minutes.
"How good is Haaland? He's a machine. I'll call his agent tomorrow."
In that match, Haaland had given Dortmund a 2-0 lead, Bayern fought back to win 4-2 — thanks to a Lewandowski hat-trick.
Bayern were willing to tear up their carefully constructed salary structure to sign the Norwegian in the summer of 2022.
Lewandowski's camp said the striker felt slighted by the German club's failure to offer him a longer-term deal, with Bayern seemingly distracted by their pursuit of Haaland.
Lewandowski had scored more than 40 goals for Bayern in seven straight seasons, scoring a remarkable 344 goals in 375 appearances.
Ultimately, Bayern's wandering eye cost them both Haaland and Lewandowski.
Haaland — who later said he "felt sorry" for Lewandowski, calling Bayern's treatment "disrespectful" — left the Bundesliga altogether.
After Lewandowski's signed with Barcelona, then Bayern manager Julian Nagelsmann sought to spread the Poland striker's goals across a dynamic front line.
While the approach had immediate effect — Bayern scored 26 goals in their first six competitive matches in 2022-23 — the goals dried up.
Nagelsmann reverted to backup central striker Eric Maxim Choupo-Moting, who again gave Bayern a focal point as the 'Stoke City reject' produced the best form of his career to score 17 in 28 matches.
Choupo-Moting however looks set to miss Wednesday's encounter with back problems.
Despite a history of scoring against Bayern — Haaland has six goals and two assists in eight games against the Bavarians — Tuesday's 3-0 victory was the striker's first win against the German champions. He lost seven from seven with Dortmund.
Since moving to City, Haaland has been spectacular, smashing records on the way to scoring 47 goals in 40 appearances.
Coming into Wednesday's clash, the Norwegian has somehow managed to up his form, with a scarcely believable 14 goals in his past six games.
Bayern have eight across the same period, four of which came in one match against a wilting Dortmund.
Big-name signing Sadio Mane has not scored since October and is returning from a one-match suspension for hitting Leroy Sane in the face after the first-leg loss to City.
Instead, Serge Gnabry will likely lead the line, the same Gnabry who said in November he did not consider himself a striker "but it's better than sitting on the bench".