What a turnaround. Picture the scene: Beijing 2008, Phelps supreme, Lochte the pretender, France sunk by 0.08sec into a deep depression in a relay with Jason Lezak a national hero.
London 2012: two days in and Phelps has a near miss and a silver to his name, Lochte is forced to settle for a silver as Agnel does to him - in spades - what Lezak did to Alan Bernard in 2008. Great day for Gaul, Muffat and Agnel, both coached by Fabrice Pellerin in Nice, Olympic champions with the keys to Paris at their beck and call back home.
How fragile the form guide, scripts hardly worth the paper they are written on. Ask Australia. Broken by a first-turn wave that defused the Missile, wet the powder in the party that followed, the Rocket a damp squib at the tail end of a sorry tale of opportunity missed in a battle in which there was just a touch of superpowers eyeballing each other at the expense of being blind to the danger from a third party.
If he US got it right on Adrian, it also miscalculated, took a risk and paid the price. Lochte? Was he the right man? But who among you would have liked to have called it? Could they have been better in different order with a different line-up? We'll never know.
We do know that the game at the Games in the pool shifted at the first turn: when Magnussen got pinned to the wall by the wash and found himself unable to regain weapon-like momentum, Australia went into maintenance mode. It was almost as though they had accepted defeat by the time James Roberts took the plunge and swam a slower homecoming relay leg than he managed on his own in the solo at Aussie trials.
Now starts the art of the chief coaches, home coaches and general entourage in the camps of they superpowers. Cometh the hour, cometh the man. How to relight the fire beneath The Missile and The Rocket?
Magnussen and Roberts will surely haste gone to bed wondering this night. Wondering what might have been. No medal at all? Silver to US, bronze to US and FRA. Maybe. On a bad day. Fourth? Nightmare. And it was.
Australia will not be alone in having mixed emotions. Even the winners may ponder a little: Bernard and the man who made him a victim in Beijing, Lezak, did not get to race the final - but each will receive a medal.
"We got our revenge," said France's Clement Lefert. "Looking good" said the 47.89 opening split from Nathan Adrian that swept him well inside his US trials win of 48.10 in the solo 100m to a best ever.
Perspective for the protagonists of 2012: there were winners and losers - and excellence all around. Yannick Agnel and his 46.74sec split were supreme, 0.04sec shy of the best ever split in textile, belonging to Pieter Van Den Hoogeband. Lezak's 46.06 from Beijing belongs to another sport and time. Lochte, in defeat, was truly impressive - 1,200 metres of excellence in the can and counting but never able to be a sprinter capable of coping with 20-year-old Agnel on a high and 1sec quicker than the American in the next lane.
"It's magical, simply magical," Agnel said. "We didn't have too much pressure. We did what we know how to do. Now, Olympic champions. It's brilliant. I gave everything in the last 50 until he cracked. In the last 10m, I saw that he was really cracking."
Tomorrow he faces Sun Yang (CHN), a different prospect, a man who looks set to take a shot at becoming the first ever to win the 200m, 400 and 1500m crowns.
Some things Phelps, the greatest of greats, will not get to top. But today he collected his 17th Olympic medal. One more and he matches Russian gymnast Larisa Latynina's 18-medal all-time record haul (of any colour) to add to his 14 golden orbs out-in-orbit standard.
He has five more cracks at the whip on that pine, including three more attempts at becoming the first man to retain the same crown at three Games. "At least I'm in a medal today," said Phelps, his disappointment showing even though he had split 47.15. Wow. So much for "is this it for Phelps". Guess we'll have to wait until August 4 for that.
Lochte was sort of fine with things, saying: "I was just really excited and I think I over-swam the first 50 and it hurt me for the last 50. But we were able to get a medal, so I guess that's good. The 100 free, I don't really swim it. I haven't swum it in a long time," Lochte said. "You would think doing distance events, I wouldn't get tired. But sprinting takes a lot out of you."
Questions for coaches, for sure. But in the sense of making sure that it is less likely to happen again. Says Phelps: "It's tough. We'd like to be on top, but Yannick has been swimming well all year and those guys put together a great relay. We tried to get ourselves into as much open water as we could. We had four great guys to get up there and swam as fast as we could. We were the ones that the coaches thought were going to have the best shot. We went out there and raced. That's all you can ask."
Indeed. Not easy to come back time and again and put yourself on the line. Kosuke Kitajima did and slipped off the podium after topping it four glorious times. But Britain's Rebecca Adlington went to bed smiling, a fine job done. The form guide rang true for once today, Camille Muffat and Allison Schmitt the most obvious candidates to take the top prizes this season, the dominant force on the way from Beijing to London, Federica Pellegrini (ITA), wilting in the heat of the moment, when bronze is well worth having.
"Another Olympic medal is just unbelievable and there is not an ounce of disappointment in me," said double champion of 2008 Adlington.
The same could not be said of the US and Australian relays. The question is: who will get back up with a spring in their step ready to fight again?