(CNN) One rarely leaves his monastery high on a hill in Vatican City. The other speaks freely -- too freely, critics say -- but has vowed silence on this matter, for now.

Two men, both clad in white, both called Holy Father, and now, both facing questions about a crucial facet of the Catholic Church's sexual abuse crisis: What did they know, and when?

Amid the onslaught of news about the scandal, it can be easy to overlook the historical novelty and high drama of this moment in the life of the church: For the first time in 600 years, there are two living popes, one retired and one active, whose fates may be intertwined, even as many of their followers are at odds.

It has been nearly a month since a former papal diplomat published a dramatic letter asserting "homosexual networks" and widespread cover-ups within the highest levels of the Catholic Church.

The diplomat, Archbishop Carlo Maria Vigano, demanded that Pope Francis resign for allegedly lifting sanctions that his predecessor, Pope Emeritus Benedict XVI, had placed on an American cardinal accused of sexual misconduct.

Whether those sanctions actually existed is a question that Francis and Benedict seem uniquely qualified to answer. But neither the 91-year-old German scholar, nor the 81-year-old Argentine Jesuit has said a word about them.

Supporters of both popes cast their silence in spiritual terms, forms of discipline and faith that truth will be revealed, eventually. Others say Benedict and Francis are loath to descend into a mudslinging fight with a former employee. Some wonder if more mundane strategies may be at work, too, such as self-preservation.

Meanwhile, many Catholics are clamoring for answers, anxious that the scandal, with its many troubling questions, could irreparably mar the church's moral reputation and undermine trust in its leaders.

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Since Benedict's abdication in 2013, the two popes have taken pains to avoid awkward images or public spats.

But in the United States and beyond, Benedict is held by conservatives as a life raft in a sea of moral relativism. Francis is beloved by liberals for his reform-mindedness, focus on poverty and openness to new ideas. While many American Catholics still like Francis, his popularity has plummeted in the last year, according to a recent CNN poll

"Maybe some people ... are not very happy with Pope Francis, so they dream about" Benedict, Archbishop Christophe Pierre, the Pope's current ambassador to the United States, said at an event Wednesday in New York.

"At times our feelings are overwhelming, so instead of looking at reality as it is, you know, we judge reality from our own feelings, our resentments, our disappointments. And so, we say, 'This Pope, I don't understand him,' and we dream about the other."

The sex abuse scandal has exacerbated tensions between the two camps as both fight for high moral ground. Francis and Benedict know everything they say can be twisted and used in those skirmishes, friends and advisers say, and are mindful of mistakes they've made in the past.

So, while their factions fight online, both popes have kept their silence about Vigano.

Theories and inter-church debates have rushed into the vacuum, to many survivors' dismay. Clergy celibacy, homosexuality, seminary culture, even liturgy have been conscripted into left-right debates about the true source of the church's troubles.

But many Catholics are urging him to be more forthcoming about Vigano's accusations. More than 46,000 Catholic women have signed an open letter to Francis, writing "to pose questions that need answers."

"We need leadership, truth and transparency," the women wrote. "We, your flock, deserve your answers now."

Other Catholics say Benedict is the pope who has questions to answer.

Vigano's accusations

The chief accusation against Francis comes from Vigano, who served both Benedict and Pope Francis as nuncio, or papal ambassador, to the United States from 2011 to 2016.

Francis has said he fired Vigano for plotting a 2015 meeting with Kim Davis , the Kentucky clerk who became a conservative cause célèbre for refusing to sign same-sex marriage licenses.

In an 11-page letter published August 25, Vigano tore into his former Vatican colleagues, accusing them of turning a blind eye to "homosexual networks" within the church, according to the archbishop.

Vigano's chief evidence of this secret Catholic subculture comes in the person of Cardinal Theodore McCarrick , the former Archbishop of Washington, who was forced to resign this summer over accusations that he molested an altar boy and sexually abused young seminarians.

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Now 88, McCarrick has denied the allegation about the altar boy and appealed his case to the Vatican after an investigation by the Archdiocese of New York found the accusation credible. He has not responded to the accusations about the seminarians.

For years, reports about McCarrick's misconduct with seminarians passed through the hands of powerful cardinals and archbishops, who apparently did nothing about them, according to Vigano. McCarrick himself was made a cardinal in 2001.

Finally, Vigano says, in 2009 or 2010 Pope Benedict XVI placed "canonical sanctions" on McCarrick, ordering him to live a life of prayer and penance away from the public eye.

But those sanctions have come under sharp questioning. Photographs and videos show McCarrick hobnobbing with church leaders, including Benedict and Vigano himself, at high-profile church events while the sanctions were supposedly in place.

The website that published Vigano's letter, National Catholic Register , now says the sanctions were not a "formal decree, just a private request" by Benedict to McCarrick.

If the sanctions were a "private request," Francis' supporters say, how was he supposed to enforce them?

Vigano's agenda has also been questioned. In addition to the Davis fiasco, he has aligned himself with conservatives opposed to aspects of Francis' papacy, including his efforts to change elements of church teachings.

But some allegations in Vigano's letter appear to be backed by documents, including a newly unearthed letter from a top Vatican official indicating that Catholic leaders had known about McCarrick's alleged misconduct with seminarians since 2000.

In the United States, conservative bishops have vouched for Vigano's character and called for an investigation of his allegations about McCarrick. The US Conference of Catholic Bishops had asked the Vatican to lead the probe, with its leadership traveling to Rome last week to make the request in person.

In a statement Wednesday, the bishops' conference said it still supports an investigation but made no mention of the Vatican.

The Vatican has not responded to requests for comment about a potential investigation into McCarrick.

'He is trying to save the church'

On the day Vigano's accusations broke, the Pope was asked about them on the plane ride home from Ireland.

"I will not say a single word about this," he said. "I believe the statement speaks for itself. And you have the journalistic capacity to draw your own conclusions. It's an act of faith. When some time passes and you have drawn your conclusions, I may speak."

Next Tuesday, the Pope will again face reporters, on a papal flight back from a four-day visit to the Baltic states.

While Francis has kept silent about Vigano so far, Pierre, his new ambassador, offered a glimpse of how the Pope may be approaching this situation.

Much has already been written and said about the Pope's Jesuit background -- perhaps too much, joked Pierre, ribbing his hosts, the Jesuit-run America Media, at Wednesday's event in Manhattan.

"They think they know everything, the Jesuits," Pierre said with a laugh.

But "discernment," a key part of Jesuit spirituality, plays an important role in Francis' life, the nuncio said. Discernment, as described in the Jesuits' Spiritual Exercises , is a way to contemplate complex situations and make sound decisions.

"It's the capacity to analyze the situation in the light of Christ and the Spirit," Pierre said.

Pierre said he saw Francis put discernment into practice while traveling with him through Mexico, where the nuncio was previously stationed.

"He is discerning all the time. He's in touch with reality. He has no idea already-made before he sees things."

"Maybe Providence is working in that," Pierre continued, "to have chosen somebody who has this capacity, this experience and this patrimony of the Jesuits and the Spiritual Exercises, precisely to guide the church in this difficult time."

One of the Pope's closest confidants, the Rev. Antonio Spadaro, said the Pope sees the Vigano letter as part of a conservative campaign to disrupt his papacy, and " draws energy from the conflict.

Still, Francis has acknowledged errors in his handling of clergy sex abuse.

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After dismissing allegations against a bishop accused of cover-ups, the Pope in April said he had made "serious mistakes in the assessment and perception" of Chile's abuse scandal. The Pope later accepted that bishop's resignation , along with several other Chilean bishops.

"He knows that he has made big mistakes on this, and he realizes that they were bad judgments, and now he wants to be cautious about not making the same mistakes," said Massimo Faggioli, a professor of church history at Villanova University in Philadelphia.

Francis also likely sees Vigano's accusations as part of a larger problem within the church: Catholic bishops face sexual misconduct allegations on several different continents right now.

(On Wednesday, the U.S. Conference of Catholic Bishops announced new policies to police bishops, including a hotline to field complaints.)

"I believe that Francis is trying to do something bigger than defend himself," Faggioli said. "He is trying to save the church.

"The problem is that the real person who should respond to Vigano's letter is not Francis," the professor continued. "It's Benedict."

The 'private' Pope

Since retiring in 2013, Pope Emeritus Benedict XVI has lived a quiet, almost cloistered life. Now 91, friends say that he is frail but mentally sharp.

In his farewell address as Pope, Benedict promised to stay "hidden" from the world, even as he knew his unique personal history would make a complete disappearance nearly impossible.

Private letters between Benedict and a German cardinal published last week in Germany reveal his concern for privacy, and that he not be seen as interfering in church matters.

In one letter, Benedict defends his decision to resign, when he became the first Pope in 600 years to abdicate St. Peter's Throne.

"With 'pope emeritus,' I tried to create a situation in which I am absolutely not accessible to the media and in which it is completely clear that there is only one pope," he wrote.

But Benedict's decision to retire as "pope emeritus" has had its own complications. Some conservative Catholics look to him as an anti-Pope, or at least an anti-Francis.

The Rev. Joseph Fessio, an American Jesuit who studied under Benedict and has published his works at Ignatius Press, said the former Pope likely knows of the efforts to pit him against Francis.

"In some ways, he has become the face of 'the Resistance,' " Fessio said, "even though he hasn't done anything to be a resistor."

When Benedict does make public remarks, conservatives often scour them for hints of unhappiness at the church's current situation, or leader.

In the piece, the author argues that Benedict's praise of a deceased cardinal's faith in the church, that he held faith in the church "even if at times the ship is almost filled to the point of shipwreck," could be interpreted as a dig at Francis. (The late Cardinal Joachim Meisner had also publicly questioned Francis' decision to open the door for remarried Catholics to receive Communion.)

Benedict's longtime aide, Archbishop Georg Ganswein, called the interpretations of the former Pope's remarks "stupid." But Fessio isn't so sure.

"He's got a very wry sense of humor, and he understates things," Fessio said. "He's not going to say, 'The church is a mess under Francis.' But his support for Meisner was a semi-coded message that he is aware of what's going on in the church right now."

Ganswein has said the former Pope will not comment on Vigano's letter, knocking down reports that he had approved its contents as " fake news ."

Besides a reluctance to be seen as interfering, Benedict may have other reasons to hold his tongue, some Catholics say.

He was Pope from 2005 to 2013, when much of the alleged misconduct outlined in Vigano's letter took place. Even allies acknowledge that Benedict did not lead the Vatican curia with a firm hand.

"When it comes to Benedict, it's damned if you did, and damned if you didn't," said Paul Elie, a Catholic journalist who has written about the relationship between the two popes.

"If Benedict knew about the allegations against McCarrick and didn't put him under sanctions, that's not good," Elie said. "And if Benedict didn't know about the allegations, that's not good either."

But Fessio and other Catholics say Francis should answer Vigano's charges, instead of making vague remarks about "scandal" and "division" during morning homilies at Casa Santa Marta, his Roman residence.

"He's attacking Vigano and everyone who is asking for answers," Fessio said. "I just find that deplorable. Be a man. Stand up and answer the questions."

Many church watchers expect that Francis, or perhaps the Vatican's press office, will eventually answer Vigano's charges. The question is, when?