One thousand matches into the Chelsea revolution under Roman Abramovich and, right on cue, Jose Mourinho is back on the scene at Stamford Bridge.
The last time he was involved in a landmark on this scale in SW6, he was in the blue corner demolishing Arsene Wenger's 1,000th game in charge of Arsenal and how he enjoyed that one. Mourinho celebrated the sixth goal in a 6-0 win as if it was the first, such was the ferocity of his relationship with Wenger.
This time, he arrives for another London derby with his Tottenham side hinting at a title challenge and signs of nascent rivalry developing with Chelsea's head coach Frank Lampard.
Mourinho likes to engage with his rivals. He locks on to test their nerve and disturb their focus. See Wenger and Rafa Benitez. Lampard knows him better than most, having worked so closely with him during a successful time together at the Bridge.
Both thrived as the Abramovich fortune transformed the club. They were good for each other. Mourinho convinced Lampard he could conquer the world by timing runs from midfield and Lampard responded with goals, including two at Bolton to clinch Mourinho's first Premier League title, in 2005.
Their paths entwine, yet it is notable how Lampard has resisted the urge to gush about Mourinho's influence since moving into management.
'Generally, when you go in different directions, you are so busy that relationships change, so it changed,' said Lampard yesterday. 'We were always very cordial — if I see Jose, if I talk about him, if we send messages between each other. We have always had a good relationship on that front.
'Naturally, now, when we are in the cut-throat end of things in these clubs that are rivals, it does change a relationship. But not in a bad way. We've got no problem with it. I certainly haven't.
'We are very competitive people. We both want to do well. When I speak about Jose, I always show how much respect I have for him in all senses. I have always got that back from him. That's where it is.'
The relationship shifted when Mourinho returned to Stamford Bridge in 2013. Lampard's contract was not renewed a year later and, at almost 36, he joined New York City, one of Manchester City's global network of clubs before quickly moving on loan to the Etihad Stadium, and scoring an equaliser against Mourinho's team as the Chelsea fans sang his name.
As a manager, Lampard has a good record against Mourinho and the young coach has been confident enough to engage in the inevitable off-the-field squabbles.
He snapped back when Mourinho claimed he was cloning Antonio Conte's back-three system ahead of the fiery clash at White Hart Lane when Son Heung-min was sent off and Antonio Rudiger heard racist abuse in the stands.
And they bickered in the technical area in the Carabao Cup in September, when Mourinho told Lampard to sit down when his team were winning and stand up when they needed him.
Some seem to think Lampard has a lot to learn. Perhaps they subscribe to the view that he was fortunate to land such an illustrious position with only one season of experience at Derby.
Jurgen Klopp offered advice after a verbal skirmish at Anfield last season. On TV, Lampard warned Liverpool not to get 'too arrogant' and Klopp responded in paternal tones, telling him to leave the arguments on the touchline, not to make the row public.
There is nothing wrong with a bit of needle and Lampard does not lack competitive courage. He is not one to take the easy option. He confronted every challenge as a player and looks determined to do the same in his new career.
So far, so good. His first season at Chelsea must be deemed a success. Failure to win a trophy rarely goes down well with Abramovich but after a summer when Eden Hazard was sold in the midst of a transfer ban, he qualified for the Champions League and nurtured talent from the academy.
At this early stage of his second season, there are further positive signs with a blur of summer signings settling into a system without losing the youngsters who helped to restore the club's identity.
Mason Mount and Reece James are firmly in Lampard's plans. Tammy Abraham has forced his way back into contention and Kurt Zouma is the preferred central defensive partner for Thiago Silva.
At the back, Silva and goalkeeper Edouard Mendy have been key to the tightening of a leaky defence. Elsewhere, N'Golo Kante is back in a central position, Timo Werner seems more threatening from the left and Hakim Ziyech has excelled since recovering from an injury in pre-season.
Precisely where record signing Kai Havertz fits in is unclear but Chelsea are becoming a balanced outfit. As are Spurs, top of the Premier League going into the weekend, and two points better off.
Mourinho teased about the riches at Lampard's disposal, being able to choose between Mendy and Kepa Arrizabalaga in goal.
'Chelsea have an amazing squad,' he said. 'To play Mendy or the most expensive goalkeeper in the history of the Premier League? To play Reece James or Cesar Azpilicueta? To play Ben Chilwell, Marcos Alonso or Emerson?
'I am not even worried about who is going to play because they only have very good players.'
It is a classic volte-face from a manager who has used the Abramovich millions more effectively then any other. When he was at the Bridge, he would demand to know why the pressure was all on him when, across the capital, Wenger had won nothing for years and was still in a job. Now, he wants to know why the pressure is all on him to deliver Tottenham's first title since 1961 when Lampard has been on a summer spending spree of more than £230million.
He knows the truth. The pressure is on Lampard. His status as a legend will not immunise him against another year without a major trophy. Mourinho just wants to crank it up a little more and he knows a victory tomorrow, spoiling the party on the 1,000th game of the Abramovich era, would do just that.