After Duhan van der Swerver, to give him his proper name, ran through England like Gulliver among the Lilliputians half an hour into an epic Calcutta Cup, we would have written it in blood that he would never again score a try to rival it. Not in this championship, not in the next, not ever.
Fewer than 50 minutes later, he delivered a contender. Van der Merwe has been having a difficult time of it this season. There was the Worcester experience for a start. Then the move back to Scotland and a lapse in form and confidence. Then an injury that took him out of the game from the end of December until Saturday, when he reappeared like a colossus and lorded it over Twickenham. You might say that the big man has his mojo back.
His second try of the day and his 16th score in just 24 Test matches didn't have the gobsmacking individual brilliance of his first - a blast for the ages that took him outside, inside and through five Englishmen in a moment of pure surreality - but context is everything in these things.
His match-winner was breathtaking in its own right, a piece of collective excellence when the heat was at its most intense, a team try that spoke to not just the skill-set in this Scotland side when playing at their best, but the scale of its ambition and the ruthlessness of its execution. When they're good, they're exceptional.
This was not a vintage Scotland performance, but it had vintage moments. It wasn't a day dominated by Finn Russell doing Finn Russell things. This was Russell's 66th cap and in more than half of those he was more of an influence than he was here.
Scotland's attack had been miraculous in its efficiency for much of the day, but with four minutes to play they trailed 23-22.
Regrets? We prepared to trot them out as part of a post-mortem. In their one serious failing going forward they'd butchered a try-scoring chance on the hour-mark, an error followed by England going down the other end and kicking a penalty. Jamie Ritchie dropped a pass earlier in that second half, a mistake compounded by a scrum penalty compounded by another penalty compounded by Ellis Genge's try.
Attack into defence. Possible points for turned into 10 points against. Moments. Everybody talks about them. Russell missed a sitter of a conversion. The fly-half kicked out on the full twice. Momentum gained and momentum lost.
These would have been the exhibits in the case for the prosecution had things gone against Scotland. And that takes us to the endgame.
They only needed a penalty in those closing minutes to get themselves in front again. A drop goal would have done it just as well. But grinding through the phases in the hope of milking something was not the way they wanted to do it. It's in the DNA of this team to attack and the wondrous nature of the score they came up with to win the Test will live long in the memory.
Many of the Scotland players should have been out on their feet after making so many tackles and absorbing so much pressure, but they summoned something quite sensational. From Kyle Steyn's initial break up the right to the subtlety of what happened thereafter, it was an exhibition in how to perform under pressure.
From Russell to Fraser Brown. From Richie Gray, making his first Six Nations start in six years, to Matt Fagerson, who ended the game with a freakish tackle count of 27. From Fagerson to Van der Merwe who drove over the England cover defence with a blistering power and a glorious inevitability.
There is a thrilling dimension to Scotland when they're on their game. They're such an exciting crew. Infuriatingly inconsistent, but utterly exhilarating at the same time. And resilient. Lord how their supporters will want to view their coolness in the closing minutes as conclusive evidence of a team that has turned a corner into the land of the contender.
England threw everything at them. Not much of it was imaginative - the variety ran the gamut from A to B - but it was a siege of the heavy mob. Scotland's tackle count rose to 229. Under all that stress, their concentration levels went through the roof. No daft mistake, no error of judgement, nobody getting overly emotional and giving England an easy in. They conceded just nine penalties in 80 minutes. Exceptional.
Townsend was emotional afterwards. No wonder. This was his fourth win over England in six attempts, a run that also includes a draw. It was Scotland's third win in a row over their greatest rivals, something they haven't achieved in half a century. The 29 points that Scotland scored was their second-highest points total at Twickenham and their third-highest against England home or away.
Can Scotland go two for two?
Reality in the shape of an angry Dragon will have entered their world by now. Before Saturday, Scotland had only ever won their opening fixture in the Six Nations on four occasions. In all four years they lost their second match. In three of the four, it was Wales they lost to.
Townsend won't want to take his players back to 2006 when a red card for Scott Murray put paid to Scotland's chances of going two for two for the first time and he won't need to remind them of 2021 when Zander Fagerson's red stymied them or last year when Russell's yellow proved so costly.
The most recent losses, particularly in Cardiff 12 months ago, are burned into the soul of all those who played and watched. Scotland won't need any telling about what Wales are capable of.
They will have precisely zero truck with the feeling that Warren Gatland's magic may have gone for good. Many of these Scottish players have beaten Wayne Pivac's Wales. Some have beaten Rob Howley's Wales. None of them have beaten a Wales team coached by Gatland. In his desperation to get something going, it wouldn't be a shock if the Kiwi was to drop that into the conversation in the days ahead.
On the evidence of week one, Scotland will be hot favourites to finally reach the promised land of two from two. They beat England despite only producing their best stuff in bits and pieces. They won with 43% possession and 29% territory. They out-scored their hosts four tries to three despite having less than a third of the attacking ball in England's 22 than England had in theirs.
That tells you something and it's that if Scotland can play to form they will win again on Saturday. Standby for another pulse-quickening, palpitation-inducing evening. One game in and this championship is already captivating.