Outside, winter whips through Wellington streets. Inside, the fate of the Megaupload accused - Dotcom, Mathias Ortmann, Bram van der Kolk and Finn Batato - rests with the power of lawyers' arguments to the highest court in the land.
Mansfield is leaning into the stronger wind.
The Copyright Act, says Mansfield, must be understood deeply, intimately even, to deliver justice in this case. And not just the law, but how it came to be.
Then he spoke for three hours about individual clauses in the legislation. Today, he takes the Supreme Court back to 2001, when work started on the current Copyright Act.
It's a hard day's work for lawyers at the Supreme Court. The hours are not long - hearings start at 10am and halt for two 15-minute tea breaks and an hour's lunch before finishing at 4pm - but it's the toughest judicial arena in the country between times.
Days, weeks, months of preparation lie behind this hearing. The original case started at the district court, then appeal after appeal, until fetching up here. For the Megaupload Four, this is the final judicial safety net to halt their long slide to a United States courtroom and potentially years in jail.
The Supreme Court is a challenging, gruelling and intimidating arena.
Kim Dotcom's lawyer, Ron Mansfield. Photo / File
The five justices sit across the court in a crescent, all looking down on the lectern. The lawyer presenting stands at the lectern, facing up at the Chief Justice. The case is presented, although the justices already have the benefit of having seen the submissions which are written and filed before the hearing begins.
They all have questions. They can interrupt at any time. And they do. Frequently.
For the lawyers, every day is opening night on our greatest legal stage. It's Everest, complete with vertigo. It's final year exams at Hogwarts and real magic is expected.
It's like trying to run across a slippery log laid across a bog while being pelted from all sides.
Sometimes the justices throw soft and easy - Winkelmann: "Can you repeat that point? I think it's important."
Other times it's a brick to the back of the head - Justice Sarah Glazebrook: "Isn't the allegation this was specifically set up to breach copyright and a lot of money was made out of that?"
It's clearly unnerving. Momentum is important and clarity is key. Lose pace or stumble and the bog surges up to the log.
Even the slightest misstep threatens the pace of delivery. There was surprised laughter when Ortmann and van der Kolk's lawyer Grant Illingworth said, "The Lord of the Rings is based on Tolstoy".
The Megaupload accused in 2012 - Bram van der Kolk, Kim Dotcom, Mathias Ortmann and Finn Batato. Photo / File
He fumbled and, just as he got it right, there was a chorus of "Tolkien" to drown out his answer. He slowed and swayed above the bog, then got under way again.
The world is their law library. They quote US law, Australian law, the House of Lords in the United Kingdom, Canadian law. A case involving German income tax legislation is referenced.
It's a battle of wits, five against one. The justices aren't there to win - it's the law which is ultimately the victor - but to test arguments. They interrogate and probe, spanning the vast territory the case has come to occupy.
At one stage, Illingworth peers out from the lectern, then says: "I'm getting a bit overburdened by paper here." He clears space, shuffling tomes.
There was an electronic casebook prepared for the justices to help them manage this complicated, internet-age, millennial case.
The court's systems struggled to make it work so hard copies were created. The judicial printer would have worked overtime.
"There's a certain irony about that," says Mansfield. It was humour lost on the bench. Justice is a serious business.
The Coatesville mansion north of Auckland where Kim Dotcom was arrested in 2012. Photo / File
