There was a moment, an hour or so into the second day of this match, when Chris Silverwood could have been forgiven for wondering what he had done.
For Silverwood, the England coach, has been instrumental in calling for his side to play on flatter wickets this summer. That way, he reasons, his batters will be able to put the traumas of India behind them and his bowlers will learn to perform in conditions where they cannot rely on the assistance that has become familiar in England in recent years.
Sounds logical, doesn't it?
But England coaches have talked this way before. Usually, when push has come to shove and series have needed to be won, they have reverted to the sort of surfaces on which their fast-medium seamers are so devastating with the Dukes ball. At 288 for 3 - with New Zealand apparently heading for a total well over 400 - it really did appear that England's limitations were being exposed.
England hadn't, by any means, bowled poorly. They controlled the run-rate so never allowed New Zealand to establish a match-defining position. It's just that New Zealand, and Devon Conway in particular, had batted with admirable composure and this pitch had offered none of the devil that has assisted England so often at home in recent years. England really didn't bowl badly during the last Ashes series in Australia, either. It's just they didn't have the attack to find much life from flat surfaces.
But in Mark Wood they do have a point-of-difference bowler. On a slow wicket, against stubborn batters, he has the skills to unlock batting line-ups. Combined with the skills of James Anderson and Co., which we know are valuable in many circumstances, he can play a vital part in the England attack. He proved that here in a spell that may well have changed the direction of the match.
It's true that Wood's record in England is modest. Ahead of this game he took his wickets at a cost of 44.91 in home Tests. At Lord's the record - eight wickets in four Tests at a cost of 52.50 apiece - was even more modest. There remains a suspicion that his skills - or at least his pace - may well be neutered by the sort of slow pitches which suit the majority of English seamers.
But in Australia? You'd think he would very much enjoy the harder, faster tracks. In six overseas Tests - not all of them played on quick tracks by any means - he has taken his 29 wickets at a cost of 23.93.
He's also a different bowler to the one who played his first 12 Tests. For those Tests, he operated off a short run and seemed to have an ankle made of crystal. His wickets in those games came at a cost of 41.73. Since the Caribbean tour of early 2019, though, he has bowled off a longer run, retained his fitness pretty well (for a fast bowler) and taken his wickets at a cost of 22.46.
He actually bowled well on day one here. And fast. Above 93mph/150kph for much of the time. Twice he hit Conway on the body with short balls; a couple of other times he might have had him caught off the edge. Given how serenely Conway has batted, that is no mean achievement. Sure, the wickets didn't come, but Wood's performance was rather better than the results.
It was noticeable, though, that his wicket-taking spell on day two was slower. About 10 percent slower, really. But it was still sharp. And it's unfair to think of Wood as just a fast bowler: he's better than that. At the start of his career, he was used by Durham as something of a reverse-swing specialist and he can still gain movement in the air and off the seam. The ball that dismissed BJ Watling, for example, drew a false stroke by leaving the batter up the slope.
His bouncer remains a valuable weapon, though. His relative lack of height means it doesn't bounce as high as might be expected and renders it hard to duck. The pull that cost Henry Nicholls his wicket was a good example of a batter not knowing how else to play the ball.
It was a huge moment in the game. It precipitated a decline which saw New Zealand lose four wickets - all of them decent batters - for six runs. From a position where 500 had looked possible, it suddenly took a merry final-wicket stand to take New Zealand to 350. At one stage, Wood's figures for the spell were 6-2-7-3.
Understandably, Joe Root gave him an extra over. But that was probably a mistake. Not just because it cost eight runs, but because Wood, with his fitness record and express pace, is probably not the man for long spells. He has to be used, like Mitchell Johnson at his best, in short, sharp spells of four or five overs. England have lots of good fast-medium bowlers. Very rarely have they had a bowler this fast with the skills and control to match.
Short spells can be tough to accommodate in a four-man attack. But with the return of an all-rounder or two, complemented by the likes of Anderson, Stuart Broad or Ollie Robinson and rotated alongside other quick bowlers such as Jofra Archer or Olly Stone, that can work.
Broad, it might be noted, has now gone five successive innings (amounting to 70 overs) without taking a wicket. While it's a slightly misleading statistic - he only bowled six overs in one innings in Ahmedabad, nine in another in Chennai and really did bowl better than the figures suggest here - it is the first time that has happened in his career. You wonder if Ed Smith, wherever is his right now, is pointing at his TV and shouting 'See! See!' to anyone who will listen.
Perhaps of more relevance, Broad also missed perhaps the easiest opportunity of his career in the field when Tim Southee sliced one to him at mid-on. In the grand scheme of the match it probably made little difference, but it did cost Robinson, on debut, a five-wicket haul. Broad will be mortified by that.
Robinson is clearly experiencing a memorable debut. But whatever you think about him - and, more pertinently, the emergence of those Tweets on the first day of this match - he showed impressive strength of character on the second day.
Alone in his hotel room overnight, he will know he had let himself down. And he will have known that it will take time and effort to repair the damage he has done to his reputation. He faces awkward conversations with family and team-mates and may face sanctions and a suspension, too. He really will have had an awful night.
But the manner in which he fronted up and apologised after the first day's play was revealing. And the manner in which he turned up on day two, was able to compartmentalise those thoughts and produce another good spell of bowling was also impressive.
Nobody is claiming a good performance with the ball makes everything OK - and it probably isn't the place of a middle-aged white man to decide these things, anyway - but in terms of skill and resilience, Robinson has shown he has what it takes to make it at this level.
But back to Wood. Is he the right man for all circumstances? Probably not. Even at Durham, it's noticeable that Chris Rushworth remains at least as potent a threat in Championship cricket. On some surfaces, particularly some surfaces at home, England may have more suitable options.
But on quick, flat tracks where England might otherwise look a bit toothless? Yes, he's a role to play there. He really is the sort of bowler who could make the difference in an away Ashes series.
There's method in Silverwood's approach. It may render England's home cricket a little less entertaining - in the sense that wickets may fall less often - and there may be sessions when they struggle for incision. But in the long term, it could make them a better balanced, more versatile side.
George Dobell is a senior correspondent at ESPNcricinfo