An ecclesial straight shooter. A reliable character. A serious man. That’s how sources familiar with Carlo Maria Viganò describe the Italian archbishop, who served as the Vatican ambassador to the United States from 2011 to 2016. His reputation makes the publication Saturday of Viganò’s written “testimony” about the Theodore McCarrick affair all the more inconvenient for those in the Catholic hierarchy who tried to bury the truth about the disgraced American prelate.

The core claim in the 11-page document is that a high-powered circle of silence for years abetted McCarrick’s career, despite his well-known penchant for sexual abuse. The circle of silence, Viganò says, included the current successor of Saint Peter. In a cryptic statement to reporters on Sunday, Pope Francis refused to confirm or deny the allegations, instead urging them to “read the document carefully and judge it for yourselves.”

The Viganò testimony bears the mark of a man seething with anger and perhaps facing the mystery of death. “It is in moments of great trial that the Lord’s grace is revealed in abundance and makes His limitless mercy available to all,” the 77-year-old churchman writes near the end. “But it is granted only to those who are truly repentant.”

For American and global Catholicism, Viganò’s dark night of the soul presents a bright clarifying moment. The document portrays a church whose highest echelons are dominated by old men who apparently don’t believe, or at least don’t take all that seriously, what she has taught about human sexuality for two millennia. And others who are willing to cut corners to protect their decadent brethren.

Either Viganò’s core claims hold water, or they don’t. Either the Vatican was informed of McCarrick’s predations as early as 2000 only to turn a blind eye, or it wasn’t.

Either Pope Benedict XVI imposed private sanctions against McCarrick in 2009-10, barring him from celebrating public Masses and cavorting with seminarians, or he didn’t. Either McCarrick’s successor as cardinal-archbishop of Washington, Donald Wuerl, was aware of the sanctions, or he wasn’t.

Either Pope Francis rehabilitated McCarrick upon taking the Petrine office, despite being warned of the abuse “dossier,” or he didn’t.

If Viganò is telling the truth about these things, then the moral catastrophe he describes is horrifyingly real.

Everything else is noise.

Noise: The suggestion, circulated by his critics, that Viganò considers himself an enemy of Francis and has been nursing a grievance over shabby treatment meted out to him upon his return to Rome from his post in Washington. On the contrary, the document suggests Viganò began memorializing his concerns about McCarrick and raising them with his superiors long before Francis became pope.

Noise: News reports that, as nuncio, he supposedly helped quash a probe into a bishop in Minnesota. This is perhaps the most ludicrous of the objections to the Viganò memo. Taken to its logical conclusion, it means that a failure to confront abuse in one instance compels silence in others.

Noise: The fact that Viganò is some sort of conservative or traditionalist, per The New York Times and other liberal outlets that have made a great deal out of the man’s theology. But would his allegations of coverup have been any more or less worthy of investigation were Viganò a theological liberal?

Which brings us to the biggest source of interference of all. As the document spread across the Catholic world, defenders of Pope Francis and the mainly liberal hierarchs implicated by Viganò pointed to the fact that McCarrick celebrated Masses and gave homilies during the period when he was supposedly under sanctions.

Doesn’t that suggest that there were no such sanctions in place?

Well, no. For starters, there’s the National Catholic Register’s confirmation of the fact of a sanctions order with Benedict’s office. Meanwhile, Monsignor Jean-François Lantheaume, a former first counsellor at the Washington embassy, told the Catholic News Agency: “Viganò said the truth. That’s all.” In his document, Viganò recounts how, when he first arrived in Washington, Lantheaume told him about the private sanctions against McCarrick. Now Lantheaume appears to be corroborating Viganò’s claims as a whole.

My sense is that, while he may be disgruntled and isolated, Viganò is no fabulist. His claims should, and no doubt will, be vetted in the coming weeks and months by the secular media and civil authorities if not by the Church. As things stand, the smart money is that Viganò won’t topple Francis. But there’s no question the Argentine pontiff faces an institutional, moral, even theological crisis.

Lay Catholics should pay close attention to those who follow the truth, wherever it may lead, and tune out the noise and its sources. And we need to pray.

Sohrab Ahmari is senior writer at Commentary and author of the forthcoming memoir of Catholic conversion, “From Fire, By Water.”