At what point did you know?
It might have come from a different moment for everyone, but the realisation would undoubtedly have hit every single person watching the second day of play at the SCG.
For some it might have been Usman Khawaja's brief and rare dalliance with the ball, the most A-list of celebrity overs.
For others, it could have been the first ball Mitchell Starc bowled with the third new ball — wide down the leg side, fumbled by Tim Paine, collapsed upon by an exhausted Josh Hazlewood.
It could have been when Pat Cummins's figures ticked over to 0-101, or when Marcus Harris misfielded one on the rope without so much as touching the ball, or when Rishabh Pant started pulling out the switch hits.
The when doesn't really matter, but the what was significant — this Australian team is done. Physically, mentally, tactically done.
You can see it in their eyes, in the way they were trudging between overs and into fielding positions. Perhaps even more tellingly, you could see it in the giggles and smirks of the Indian contingent sitting comfortably in the SCG viewing area.
They've earned this, the Indians. They've been subjected to this torture on many an Australian tour — by Michael Clarke or Steve Smith or David Warner or Ricky Ponting — kept in the field for days on end and shown no mercy by a superior opposition.
Revenge must be sweet. There are still three days of this Test remaining, but Friday felt like India's coronation. The day they not only beat Australia, but broke its spirit, pummelled it entirely into the dirt so hard there is now no chance of any hope growing.
Talk had turned to a Cheteshwar Pujara triple-century before he had even reached 200, such was the ease of his command over the bowling. Stunned silence filled the SCG when he instead chipped a catch back to Nathan Lyon instead of posting something record-breaking.
Rishabh Pant had spent the series threatening to turn explosiveness into something of genuine substance, and found the right balance on day two. Only 21 years old, Pant is going to be terrorising Australian bowlers and stump mics for many years to come.
India deserves all the praise it has got and will continue to receive as this Test winds towards delivering the historic series win it has craved. You cannot overstate how impressive the execution of its expertly hatched plans have been.
Devoid of Indian scalps, Aussies taking aim at their own
That's one half of the story. The other is Australia — its faults and its growing divides.
The noises out of the camp after a desperate day one were not positive. They spoke of a team short of ideas and unconvinced about the ones they had, an exhausted side that doesn't know how to stop its opposition and probably doesn't have the energy left to try.
"I think the bowlers wanted one thing, Tim wanted one thing," bowling coach David Saker said on Friday morning.
"Last night we talked quite heavily about the day … Some of it was quite aggressive and that's not like me usually. JL (Justin Langer) wasn't happy. The bowlers know that."
Saker's words back up those of Lyon, who couldn't help but vent his frustration at a plan gone awry. When Lyon, the ultimate team man, is forced into public displays of admittedly minor dissent you can be sure things aren't quite all hunky dory behind the scenes.
Combine that with the widespread mystification at the behaviour of the national selectors and the ongoing sniping between the three banned players, and the picture really doesn't look great.
To his credit, Paine will keep on fronting up. He made no excuses in his post-play interviews, and had enough humour left to cheekily answer a journalist's phone during the press conference. The brave face is an obligation of the role, but Paine wears it more naturally than most.
But even he must know it too. If the rumblings of discontent are even remotely true, half the battle for the rest of this Test will be to keep the atmosphere somewhat positive — a tough ask for a rookie captain with a badly unsettled team.
We'll get more of an insight into the mental state of Australia on day three. The batting effort is futile — only the small matter of a few individual careers is on the line — but a meek rollover will paint a damning picture.
There are losses, and then there are losses. It's vitally important for Australia this doesn't become the latter.