In the beginning, when South Africa issued their first real challenge to Australia in this series, Aiden Markram scored a century. It was in the second innings of the Durban Test, with South Africa chasing a target of 417, and though they lost by 118 runs, Markram's 143 was not all in vain. For as long as he was at the crease, South Africa could still consider themselves in with a chance. An outside chance, but a chance nonetheless.

At the end, when South Africa geared up to issue their final challenge to Australia in this series, Aiden Markram scored another century. It was in the first innings of the Johannesburg Test, when Australia took the field without Steven Smith or David Warner or Cameron Bancroft or Mitchell Starc and the mental state of Australia already suggests Markram's 152 will not be wasted. South Africa have a chance to win their first series against Australia at home since readmission, a very real chance.

In between those two hundreds, enough has happened to make a very good movie. Something that could be titled "Sport: How Not to Play It," and the one person the makers wouldn't cast is Markram. He is one of the few players who have come out of this series squeaky-clean, halo-ed even.

His performances on the field - two hundreds and an average of 63.28, against the No.3 ranked side in the world - have answered questions about how good he really is, after a 97 and two hundreds against Bangladesh and Zimbabwe in his first three Tests, and a 94 against India subsequently. As Markram himself said, "as a batter, you want to score runs against big sides."

But what has also made Markram stand out is his conduct: respectful, schoolboy-style respectful - the kind of schoolboy that raises his cap to shake hands and makes sure the collar on his blazer is sitting right - soft-spoken, even when there are serious issues at hand, and seemingly able to put all the sideshows into a box, in a corner of the room, lock it up and throw away the key.

At Kingsmead, it was Markam who was at the other end when David Warner spent two hours between lunch and tea on the third day verbally abusing Quinton de Kock. Afterwards, he insisted with typical politeness that nothing that was said crossed the line. Clever answer. He didn't say nothing that was done crossed the line, knowing full well what had taken place in the stairwell at the tea break but steering clear of involving himself in any of it.

At Newlands, it was again Markram who was batting when television cameras caught Cameron Bancroft with the small, yellow object we now know to have been sandpaper. The visuals were shown on the big screen but Markram didn't see them. He also didn't suspect anything was amiss. That day he explained that he bats in a "bubble" and doesn't pay attention to what's happening around him. Today, Markram said it again. "I try to get into that bubble, it's like a space for me."

The same used to be said about Jacques Kallis, who was able to shut the world out and just bat. And Australia have first-hand experience of that. During the Boxing Day Test of 1997, when Kallis spent nearly six hours compiling his maiden hundred, Glenn McGrath, Shane Warne and co. threw every disparaging word they knew at him. But Kallis just kept on batting. Similarly, Markram has shown an ability to just keep on batting, while batting more aggressively than Kallis typically did.

Comparison can be career-killers, so we'll stop there and simply admire Markram's proactive batting style. From the end of the third over, when he sent Josh Hazlewood to the midwicket boundary, Markram was ahead of his opening partner, Dean Elgar, and he stayed there. After the first hour Markram had 24 runs from 49 balls; Elgar 9 from 35.

By their own admission, Australia started off quite flat and allowed South Africa time to settle down but Markram still needed to watch out for the "nibble" he said was on offer throughout the day on a pitch where neither he nor anyone else "ever really felt in".

Markram said during the afternoon session that "AB [de Villiers] strolled down the wicket and said, 'Shew, this is tough, I don't feel like I am batting too well," and the pair realised they would have to absorb pressure rather than force the run rate. But once they saw off that period, batting became easier and though de Villiers did not push on to three figures, Markram did, and to a career-best score.

In the process, he earned a second public statement of praise from the India captain Virat Kohli, who posted a tweet that consisted simply of Markram's name and multiple emojis of approval. When Makram was batting at Newlands last week, Kohli called him a "delight to watch", and Markram has taken note of what one of his most famous admirers has had to say.

"It's quite a special feeling. There are a lot of players that I look up to who are a bit older than me and he is one of them," Markram said. "His competitiveness is something to admire and his motivation to keep scoring runs is something I've tried to take on board."

Markam's interaction with Kohli, when India toured South Africa earlier this summer, was fairly limited but they stood as opposite numbers for five of the six ODIs, when Markram was thrust into the role after Faf du Plessis was injured. South Africa lost four of the five games, Makram did not make a score higher than 32, and his confidence took its first knock at international level. "I was pretty down" he said. "I felt quite responsible for the series loss and personal performance didn't go too well either."

He also experienced for the first time something that he is expected to live through many more times in his career: captaincy. Markram has been touted as the future national leader, and all the qualities he has espoused in this series explain why. It won't go unnoticed that his form is red hot and that the current captain was out for a first-ball duck, after six scores of 20 or less in this series so far.

But Markram indicated he may not be ready for all the pressures that come with being in charge just yet. "I don't think you're going to see anything a hell of a lot worse than what we've seen in the last few weeks," he said. "It was a bit of an eye-opener to be honest."

The events of this last month have shown him it takes a lot more than big performances and a big personality to captain a side. It takes a big heart too. From what we've seen in this series, that's exactly what Aiden Markram has.

Firdose Moonda is ESPNcricinfo's South Africa correspondent