The final weekend of the Australian Open will likely be the last chance to experience a level of dominance that tennis - or any sport - rarely sees.
And watching Roger Federer will be pretty cool, too.
But after a remarkable fortnight featuring unlikely tennis upsets and improbable resurgences, the match at the top of the billing in Melbourne should be tonight's showdown between Serena and Venus Williams.
In addition to illustrating just how well the wind in Auckland prepared the sisters for the first grand slam of the year - second-round exits and injury withdrawals notwithstanding - the encounter will surely bring to a close the greatest sibling act in sporting history.
Have we ever been treated to members of the same family reigning so supreme for such a long period? Will this indeed be our last chance to savour the sporting drama the American sisters provide? And should Serena take one for the team and temporarily cede centre stage to her big sister?
Those questions are set to be answered at Rod Laver Arena tonight ... and in this column right now.
To tackle to first query in a word: no. While sport abounds with siblings taking a rivalry from the backyard to the international stage, what the Williams have achieved is peerless.
Vitali and Wladimir Klitschko controlled a weak era in heavyweight boxing but upset fans by refusing to fight each other. Peyton and Eli Manning each won two Super Bowls but the younger quarterback never attained his brother's heights. And Alistair and Jonny Brownlee have ruled triathlon throughout the decade but, with all respect, it's only triathlon.
The legacy of the Williams sisters, on the other hand, appears unimpeachable: 29 combined grand slam singles titles, 120 combined tournament wins, a combined lifetime spent ranked No 1 in the world.
This is where a dissenter would point out how all that combined success is merely a result of Serena, and that argument is based in reality. After all, another win tonight and one of the greatest athletes in any sport will own her 23rd grand slam, breaking a tie with Steffi Graf and leaving her trailing only Margaret Court.
But that overshadows how, once upon a time, the sisters were almost equals: by the end of 2008, Venus' seven slams saw her trailing Serena by two. And it also marginalises the fact those seven titles leave Venus in a tie for 12th all time, how her 80 singles finals place her inside the top 10.
It's just that, when Serena went supernova, Venus stopped winning slams. And one of the reasons for that drought - Venus in 2011 being diagnosed with an auto-immune disease that threatened her career - also explains why tonight's match should be so treasured.
Now 36 and with retirement a constant question, this must be the last time the stars align and allow the elder Williams another climactic contest with her sister. And, with that in mind, I present a proposal to the serial winner that is Serena.
The 35-year-old offers no mercy when her blood is on the other side of the net and a trophy is on the line, winning six of the pair's eight grand slam final meetings. And Serena is, naturally, a hot favourite to pull within one of Court's record tonight.
But, as she has shown again this week, Serena is still the superior force in women's tennis and there will certainly be more chances to move to the top of the grand slam charts.
Let Venus have this one, huh? If for no other reason than as a favour to this fan, who will be watching eagerly from one of your favourite cities.