The best thing about the great passages of Test cricket is that often you only realise they're happening when they're already well underway. Like the memory of a dream, quite where everything started is unclear, the only option is to simply let the unfolding events wash over you.
The immediate period after a lunch break is usually a sedate one, players easing their way back into the game, fans slowly trickling back to their seats – nobody, it seems, gave Jofra Archer that memo.
It is rare that an over of high 80s fast bowling – containing the wicket of an Australian captain as well – can be described as a loosener, but that perhaps more than anything gives a flavour of the madness that was to come.
Like trying to define the age of a piece of antique silverware devoid of any maker's mark, pinpointing where a great spell began is more a question of intuition than an exact science – wherever it started, for a period after lunch all that mattered was Archer and Steve Smith locked in a duel for the ages.
Archer was bowling fast, three times in the second over of his spell he breached 90mph, Pat Cummins the recipient on every occasion – today there would be no post-lunch lull, the usual empty seats had been filled, 30,000 pairs of eyes flicking up to the scoreboard after every delivery waiting for the readout from the speed-gun to flash up.
This was a tropical cyclone of a spell, at one point Archer bowled 16 consecutive deliveries that were all over 90mph, but at its eye was the contest against Smith – a micro-drama that appeared to stretch time, action seemingly worthy of hours in reality crammed into possibly less than twenty minutes.
Future cricketing historians poring over the annals might mark the second ball of Archer's third over as the moment that the contest truly began, Smith flaying the ball dismissively wide of mid-off for four, a back-foot drive worthy of any of the Caribbean greats.
Archer responded with a bouncer, left well alone, so short is was called wide – then came the real fire. The next jagged back, 90mph breached once more, thudding into the back elbow of Australia's former skipper – a painful forewarning of what was to come.
Three balls later Smith was struck again, he tried to duck under a bouncer but the ball smashed into his forearm – physio called on, strapping applied, the discomfort as clear and obvious as you'd expect from a blow at that speed.
Lord's was energised, how could it not be with bowling at this speed, breath collectively held for an over as Jack Leach sent down a maiden to Cummins.
Then, it was back on, a roar slowly making its way around the stands – a bandaged and shaken Smith back in Archer's firing line once more. He escaped the over unscathed, but only just, edging a bouncer over Bairstow's head, then uncontrollably lobbing the next ball up in the air only to see it land safe – considering the ball was 94mph, perhaps he was just pleased to get the bat on it at all.
It was an over finished in style, Archer thudding the ball into the gloves of Smith, the Australian just managing to keep it down in front of Buttler at short leg – 96.1mph flashing up on the scoreboard to astonished gasps all around the ground.
It seemed improbable that Archer could have anymore overs still left in him, but again he returned, now well into that stretch of 16 consecutive 90mph+ deliveries, the six sent down to Cummins as thrilling as they were frustrating only because they were delaying the resumption of the fascinating duel with Smith.
Before the game, Justin Langer had questioned how Archer's stamina would fare the more spells he had to bowl. This was quite the riposte, it was his fifth of the innings and the most ferocious many England cricket fans have probably ever seen.
When the end of the contest came it was fairly sickening, Smith struck in the head by a bouncer that didn't quite get up, falling worryingly to the turf – the fervour and excitement of the crowd reduced to a concerned murmur in a matter of seconds.
Fortunately, Smith was ok, reluctantly retiring hurt, this heavyweight contest ending with a split decision.
And just like that the spell was broken, one of cricket's great duels ever, its memory destined to forever live on for all those lucky enough to see it.