The first over of a session provides an opportunity to lay down a marker, and to set the tone for what lies ahead. After England's weary players emerged for the final time on the day that was theoretically the halfway point in this series, Will Jacks certainly managed that.
Jacks' first ball after tea was short and wide outside Usman Khawaja's off stump, and hauled out to deep midwicket - one of four boundary-riders - for two. Jacks overcorrected, and consecutive half-volleys down the leg side were swept away for four. Khawaja milked a single, Travis Head hit a long-hop to extra cover on the bounce, and Joe Root misfielded the sixth at cover.
It was a 12-run over that laid bare the gulf in quality between these two bowling attacks. Australia's three main seamers have 805 Test wickets between them to England's 141 - with Ben Stokes (238) unused after his exertions with the bat - and Australia's spinner has taken more wickets in Tests at Adelaide Oval than England's has taken in his entire first-class career.
Nathan Lyon did not take a wicket after his first over but was unerringly accurate in his next 27 to the point of conceding just 2.50 per over. Jacks' economy rate in this Test match is more than double Lyon's (5.43) but the gap between the two offspinners is more like a chasm: comparing the two is unfair, even cruel.
Jacks' initial selection in England's squad for this tour made some sense as all-round cover: the apparent logic was that if Stokes was unavailable for a Test, Jacks would replace him at No. 6, and a fourth seamer would replace Shoaib Bashir. Instead, after three years out of the picture, Jacks has found himself playing back-to-back Tests as England's main spinner and No. 8 batter.
It is a remarkable situation, and one which lays bare the confusion that has engulfed England's dressing room after two chastening defeats. "We all know why he was picked," Jeetan Patel, one of their assistant coaches, said of Jacks, "and that was because of the first two games, where we felt like we did need that extra batting cover."
His inclusion is therefore a damning assessment of England's top order; so too of Bashir's form and confidence after two years being hot-housed specifically with this tour in mind. "Look, Bash is bowling fine," Patel insisted, when asked if he had become unselectable. "Would we have liked to have Graeme Swann out there? Probably, but we don't have him." It was hardly a vote of confidence.
In his third over after tea, Jacks bowled a ball that was so short and so wide that he shook his head as though embarrassed to have taken a wicket with it when Khawaja managed to edge it behind to Jamie Smith. It gave him an unlikely opportunity to turn the screw, as Cameron Green walked out on a pair; Jacks served up a wide half-volley first-ball, which Green drove for four.
"I don't think he's bowled poorly," Patel said. "They've played him very well. They've used the crease. They've got deep. They've run down at him. They've used the off side and the leg side, and they've looked to score, looked to put him under pressure. That's probably what you would do against a spinner of Jacksy's nature, where it's not his frontline skill, as such." He was saying the quiet part out loud.
This is hardly Jacks' fault. Since he played his first two Tests in Pakistan three years ago, he has played 14 County Championship matches and 138 T20s, nearly ten times more. In T20, a single is a win for the bowling team. Given the context in which his bowling has developed, is it any wonder that Jacks bowls so many cut-balls, and gets milked for one quite so often?
His inclusion was a desperate gamble that has, predictably, backfired. England hoped that their batters would finally deliver in Adelaide after four misfires and that their four seamers combined would deliver 20 wickets between them, rendering Jacks a spare part; his mere presence at the crease, with bat or ball, has served as proof that something has gone wrong.
England may well have backed the wrong horses for this trip, but the alternatives are hardly compelling. Jack Leach took six wickets at 53.50 in Australia four years ago, conceding more than four runs per over, and Liam Dawson's limitations were laid bare in his comeback Test against India, when he failed to take a wicket across 47 second-innings overs.
The reality is that even the world's best spinners have struggled to make an impact when touring Australia over the past decade, and England's production line is bare. Since their last win here in 2010-11, no England spinner has taken more wickets in Australia than Root, whose part-time stylings were chopped away with disdain as Head cruised towards his hundred.
There were moments on the third day when England bowled admirably. Brydon Carse bowled a brilliant spell straight after lunch, his best since Perth, but could not find the edge; Josh Tongue had Marnus Labuschagne and Green well held at slip by Harry Brook; Jofra Archer gave nothing away, bowling on a third consecutive day in the heat after two-and-a-half hours' batting.
It all felt futile. England blew one chance in Perth, missed another in Brisbane, and have spent the past week confusing their squad further with a series of mixed messages. The result is this: a white-ball specialist, picked to reinforce England's batting line-up, haemorrhaging 212 runs across 39 overs and thereby asking even more of the top order that he was picked to bail out.
Two-and-a-half hours after his looseners, Jacks dropped short and wide to Head yet again; Ben Duckett put in a sprawling dive on the rope at point but could not prevent the tenth boundary that Jacks had conceded in 12 overs since tea. Australia had scored 152 in the session without breaking sweat: it was an ugly end to another ugly day, as England's Ashes dreams faded to nothing.