In the witness box at Belfast Crown Court, Gerry Adams had nowhere to hide. He has been ducking and diving and evading the truth for decades. But this time, nobody would let him.
In a forensic cross-examination by defence barrister Eilis McDermott, at his brother's first trial in April, when he was a prosecution witness, Mr Adams' every word and action in dealing with Liam's horrific sexual abuse of his daughter, Aine, was under scrutiny.
The results were devastating. But, this time, his evidence – that he had been estranged from his brother after learning of his paedophilia and had done everything possible to help Aine – was severely undermined.
Ms McDermott asked if he agreed that an allegation of child sexual abuse was a matter of "fundamental seriousness", not just because of the "harm and damage" to the child, but because of the danger to others.
"Yes, that's true," answered Mr Adams. And then a deluge of incidents were disclosed showing that, contrary to what he professed, he had taken no decisive action to protect children in either his own family, or his West Belfast constituency.
Mr Adams said that, when he learned of the abuse allegations, he had immediately told Liam's new partner, Bronagh, with whom he had a two-year-old-daughter.
Ms McDermott suggested he didn't. "Well, I did... at her home in Andersonstown" in 1987, he protested. "You see, Mr Adams, your brother's wife, she didn't have a home in Andersonstown until 1999, or 2000," the barrister stated.
He was asked if he had reported the abuse allegations to social services in Donegal, where Liam was living in 1987. "No, I didn't," he said.
Even the excuses he cited for his "memory loss" lacked consistency.
"The decade we're talking about was an extremely busy time for me in terms of my political work," Mr Adams opined. "These were the years in which cessations were arranged... in which the Good Friday Agreement was negotiated and so on."
"Mr Adams, the Good Friday Agreement certainly wasn't being negotiated in 1987, was it?" Ms McDermott asked.
Mr Adams had previously told UTV journalist Chris Moore that "Liam went out of the country" after the Buncrana meeting and they'd been estranged. The court was told that, apart from a few holidays in Spain, Liam had never left Irish soil.
His account of Liam being "out of my life more or less for the next 15 years" was proven to be "another lie", as the barrister said.
Photograph, after photograph of Mr Adams with his brother was produced in court. The Mansion House in Dublin in 1991: "It shows you, isn't that right, on the left and is that Mr Martin McGuinness?" Ms McDermott inquired.
Liam's wedding in 1996: "You are standing, again on the left, Mr Adams with your arm around your brother Liam's shoulder, is that right?"
The pictorial evidence was so overwhelming he was reduced to "Yeah", "Yep" and "Yes".
Canvassing in Dundalk with his brother during the 1997 Dail election; presenting flowers with him to women in Co Louth. And there was Liam at Clonard Youth Club in 2003, standing beside Martin McGuinness.
"Was Mr McGuinness the Deputy First Minister at the time?" Ms McDermott asked. It stretched credibility to breaking-point when the man who helped negotiated the peace deal replied: "Well, I don't recall. When was the power-sharing arrangement set up?" "I thought you might know, Mr Adams," the barrister stated.
Mr Adams's 2001 book, An Irish Journal, was shown to the court. "To Liam, Bronagh and your family. From Gerry xoxox," it was signed. A copy of his 1994 ard-fheis presidential address was likewise inscribed.
"I am putting it to you, Mr Adams, that far from your brother Liam being out of your life for about 15 years, he was very much in your life. You had regular contact with him," Ms McDermott stated. "I'm doing my best to recall the exact timeline," was the best he could muster.
Did Liam begin working at Clonard youth centre in 1998, he was asked. "He may well have," was the vague answer.
"I'm suggesting to you that you know he went to work there in 1998, because he was living with you at the time for a period of six weeks," the barrister said.
"Was he living with me? ...I have no recollection of him living with me for six weeks," said the Sinn Fein president.
He had tried his best, he protested, to stop Liam working at Clonard. He alerted the authorities there. But the veracity of his statement crumbled when he was quizzed on the specifics. The only person he could recall raising it with was a now-dead priest.
He told the court he had often asked Liam to leave Clonard. "Did you ever say to him, 'If you don't get out, I'm going to have to go to the police'?" the barrister asked. "No," admitted Mr Adams.
His assertion that he'd bent over backwards to co-operate with police was likewise deconstructed. He denied giving detectives only 40 minutes of his time in 2007.
"I could have been available to police for as long as they needed me. The issue of 40 minutes never came into it," he insisted.
A detective's note of the meeting was read to the court. "Met with G[erry]A[dams]... had only 40 minutes. Felt if had not taken a statement then would not have got one."
Though he denied "saving his own political skin" had been his motivation, the overwhelming impression was that his every word and deed in the whole sordid tale was aimed at protecting not children, but the Adams's name.
The Sinn Fein president portrays himself as a credible, caring and compassionate public figure. The chasm between the myth of Gerry Adams and the reality couldn't have been clearer. In the witness box, he was in a position he loathes and now we can understand why. He wasn't dictating the terms of the debate.
He was decisively pinned down. In a clinical courtroom, only hard facts are permitted. Waffle about the peace process, family privacy or expressions of phony sentiment isn't permitted.
It was in these circumstances that we saw the absolute unravelling of Gerry Adams.