Manchester - Pep Guardiola's imminent arrival in the Premier League is a game-changer not just for Manchester City but for English soccer, bringing a coveted, visionary coach to a club already having a stated aim of being a "leader in the world of football."
City has thrown down the challenge to England's other powers, and their response will be fascinating.
Nowhere more so than across town at Manchester United.
United used to take pity on City. Manchester derbies were embarrassing mismatches - City won just one of 26 meetings between 1981 and 2002 - and some United fans even craved a stronger city rival.
Now they have one, and pity has been supplanted by jealousy with news that Guardiola will leave Bayern Munich at the end of the season to take over at City on a three-year contract.
What United supporters would give for City's attacking style of play, its recent haul of silverware, its sparkling $300m academy, and now its new coach. It's hard to believe that 17 years ago, United was on its way to a Champions League-Premier League-FA Cup treble, while City was languishing in England's third tier.
United can only dream of winning the Champions League these days. The way things are going under Louis van Gaal, the team won't even be in the competition next season.
City's hiring of Guardiola must be a worry to the United hierarchy, which has to act fast. Meandering along with Van Gaal will surely see United slip further behind - it's hard to see City not improving with Guardiola's pull and his demanding leadership - and the lure of the currently unemployed Jose Mourinho might just have intensified in the corridors of Old Trafford.
United has spent $375m on new players over the past two seasons, seemingly to little effect judging by the string of uninspiring displays in recent months. The U.S.-based Glazer family, which owns United, must now sign off a similar wave of signings to keep in touch.
Yet, put yourself in the shoes of a Paul Pogba, a Robert Lewandowski or a John Stones - three of the many players who may have been on United's radar and are now being linked with City since Guardiola's arrival was announced on Monday. City's appeal must surely be greater for players seeking a combination of trophies, luxury and personal improvement.
That attraction even goes as far as the academy setup. City, with its sprawling, state-of-the-art 80-acre campus, is picking up the best youngsters in the region - even former United players Robin van Persie and Phil Neville have sent their sons there. United's once-famed academy, meanwhile, is reportedly in turmoil, without a director since May last year, and currently undergoing a root-and-branch review.
City's under-14 team beat its United counterpart 9-0 this season, and United's under-18s lost 11 straight league matches.
United can still rise again. Commercially, the club is unrivalled - barely a week goes past when United isn't announcing a new, global sponsorship deal - and it has the largest annual revenues in English soccer. It is also still widely regarded as England's No. 1 club because of its history and trophy haul of a record 20 league titles and three European Cups.
Soccer players look for more these days, though. Being in the Champions League is a necessity to entice the best, potentially a concern for United, but Guardiola's name may be just as big a pull.
Backed by the wealth of its Abu Dhabi owner, City has established itself as the biggest force in England and can only get bigger with Guardiola in charge. Its players appear to be coasting under the avuncular Manuel Pellegrini and they are still contending in four competitions this season. Imagine the levels they can reach under Guardiola.
No wonder City's shadow is looming large over United.
The "noisy neighbors" - as Alex Ferguson once called City - have just gotten noisier.