For a working-day morning, Eden Gardens packed in surprisingly well. This time of year, Kolkata tends to offer the best version of its usually testing weather, and the stadium felt it. The galleries filled up with a noisy crowd, and a thin drift of expectation hung in the cold morning air. The stage was set. Chants for Bumrah were belted out from different pockets as he ran in. But this isn't a neatly-scripted fable that bends to your whims. Because what came up first was chaos. Swing, no-bounce, extra bounce - an entire buffet of the untamable variety.

Then, Mohammed Siraj endured a false start. Aiden Markram and Ryan Rickelton helped themselves to quick runs in a phase that usually shows a lot of love to quick bowlers here. In the South African dressing room, Temba Bavuma would've sunk into his chair with the satisfaction of having thrown the first punch at Shubman Gill at the toss.

But as is his wont, Bumrah made him, and the hopeful thousands at the venue, sit up. "When I bowled the first over, everything happened. The ball swung, it stayed low, it went high. It was a little difficult to understand what was the right length. So you keep bowling and you keep figuring things out that, okay, it's shaping in this manner," Bumrah said at the end of the day.

It took more than 10 overs for that realisation to materialise into anything tangible. By then, Shubman Gill had already been forced to dismantle his optimistic, well-populated slip cordon. In his sixth over of the morning, Bumrah got the better of the variables that were unsettling him, and squared up Rickelton from round the stumps. An over later, the same unpredictability of the conditions sided with him to nick off Aiden Markram. Inside the first hour, Bavuma was off his chair and into the middle, while his batters began to mistrust the bounce and get tentative.

"Basically, it's the harder ball game. When the ball is nice and hard, maybe the deviation would be a little quicker. When the ball becomes softer, the deviation lessens and then your accuracy comes into play," Bumrah offered.

There isn't much nuance to how Shubman Gill uses his best bowler in a home Test. Just a day before, he spoke about how he didn't have to worry about workloads in these conditions where spinners shoulder longer shifts. That freed him up to pick his moments and unleash Bumrah. After an opening burst of 7-4-9-2, Bumrah strode out with purpose again right after Lunch. There was no scope for a mid-day slumber here, not for the fans slowly returning to their seats and definitely not for the locked-in pair of Tony de Zorzi and Wiaan Mulder, who'd already batted 11 overs together. But in the first six overs of the session, both were sent packing with Bumrah cracking open de Zorzi's resolve. Bumrah struck a nerve with the crowd on the very next ball, flooring Kyle Verreynne with a welcome appetiser of the inswinging-yorker variety.

Even with a shorter spell this time (5-0-13-1), Bumrah left the visitors too groggy to quickly find their composure again. Bumrah was at the wheel of a day-defining middle session where India knocked back five wickets, and then came back to spearhead the last one again, closing it out exactly like he began the morning. Uneven bounce conspired with him to snuff out Simon Harmer, before he brought out the oldest two-fold trick from the fast bowling manual for Keshav Maharaj. The No. 11 was hurried by a bouncer first ball, and then got an inswinging yorker on his boot while he was stuck deep inside the crease.

As the two South Africans walked off following the umpire's decision, Bumrah stood in the middle of the pitch, both his arms raised in celebration for his 16th Test fifer. His teammates, who've seen this movie play out so often in the last few years, swarmed him anyway. The Kolkata crowd, meanwhile, was off its feet, applauding the man who accentuated the return of Test cricket to these corners after six long years.

Bumrah found admirers in the opposite camp as well. South Africa batting coach Ashwell Prince doffed his hat to the different bursts of genius that the pacer conjured, while lamenting that his batters couldn't combat the unevenness of the Eden pitch.

"But that's the challenge of Test cricket, right?," Bumrah reckoned. "Wherever you go... to different conditions, the challenge is different. We went to South Africa and in five sessions, a Test match was over. It's never a simple answer that this is how the wicket should be," he said.

In all the wreckage of the day and such a post-mortem, the missing subtext sat right in front of you: this was also the full, unforgiving experience of facing one of the world's very best.