The story of Fr Brendan Smyth is not just one of a predatory abuser who ruined the lives of countless children.
It is also one of cover-up and of turning a blind eye, the default position adopted over a period of decades within the Catholic Church, not just in Ireland, but in the UK and the US.
Belfast-born Smyth's reign of terror lasted over 40 years.
This was only made possible through the willingness of church authorities to move him on whenever allegations surfaced.
Smyth was moved from parish to parish and country to country, often in circumstances where his order, the Norbertines, failed to inform either the local bishop or the civil authorities of his history of sexual abuse.
There appeared to be no appreciation of the damage he was doing and the lives he was destroying.
At all times, the main motivation appears to have been the avoidance of scandal.
Why else would young children abused by Smyth be forced to sign undertakings not to discuss their allegations?
It may never be possible to gauge the full extent of Smyth's monstrous activities.
Previously, it had been thought he may have abused around 150 children in Ireland, Scotland, Wales and the US.
But the evidence heard yesterday at the North's Historical Abuse Inquiry, some 18 year's after his death, suggests there could have been hundreds of victims.
Over the next week the inquiry will examine what opportunities there were to prevent Smyth carrying out abuse. It will look at the actions, or inactions, which allowed him to continue unhindered.
In a statement, the head of the Norbertine Order, Fr William Fitzgerald, said Smyth should never have been ordained into the priesthood. He acknowledged the "immense" failure of the order.
But the failures didn't stop there. They went right to the top of the church in Ireland.
Cardinal Sean Brady took part in a diocesan "investigation" into Smyth in the 1970s.
Then a diocesan secretary, he never alerted the civil authorities.
His abject failure to do the right thing did not harm his career and he would later become Primate of All Ireland.
Even when Cardinal Brady's involvement in the Smyth affair became known in 2010, he was able to remain in situ for a further four years.