(RNS) The Vatican has always been a hothouse for conspiracy theories, and a new controversy over the so-called Third Secret of Fatima is showing just how persistent such fixations can be — to the extent that the latest episode even forced Pope Emeritus Benedict XVI out of seclusion to refute claims that he once shaded the truth about the mysterious prophecy.

At the same time, however, the new Fatima saga has overshadowed what could be a much more problematic bit of Vatican intrigue: how Benedict’s presence as the first ex-pope in more than six centuries is continuing to raise questions about the nature of the papacy, and the authority of Francis, the current pope.

So far, most of the media attention has been focused on the three Fatima “secrets” that the Catholic Church believes were vouchsafed by the Virgin Mary to three shepherd children in Portuguese town of Fatima in 1917.

Two of the prophecies were published back in the 1940s but the Third Secret – supposedly too dangerous to reveal – remained sealed in the Vatican archives.

That silence naturally inflamed the religious imaginations of true believers in the secret prophecy.

So to calm the fevers, Saint John Paul II ordered the Third Secret published in full in 2000. He also had his top theologian, Cardinal Joseph Ratzinger, issue an accompanying explanation of the prophecy’s graphic descriptions of persecution and murdered popes and bishops.

But conspiracy theories die hard. And this year, shortly after the May 13 feast of Our Lady of Fatima, a traditionalist blog published claims that Ratzinger – who was elected Benedict XVI after John Paul died in 2005 – told a friend that there was more in the secret than had been published.

The blog also suggested that the hidden bits were dark predictions about the current papacy of Pope Francis and the turmoil, and even heresies, that some conservatives believe Francis has encouraged.

The charges were so explosive that the Vatican press office on May 21 issued a forceful denial directly quoting the frail, 89-year-old former pope. Benedict called the reports “pure inventions, absolutely untrue” and confirmed that “the publication of the Third Secret of Fatima is complete.”

Of course, not all Fatima devotees were convinced, and some argued that the denial was just part of the conspiracy – and so it goes.

From Dan Brown’s “Da Vinci Code” to rumors of rigged conclaves, from the medieval legend of “Pope Joan” to whispers of Masonic plots and papal assassinations, Rome’s secretive culture sprouts intrigues like mushrooms.

But just as the Fatima story was making headlines, Benedict’s longtime personal aide, Archbishop Georg Ganswein, delivered a surprisingly candid speech that reignited the equally potent issue of whether there are two popes or one, or whether the papacy itself has been redefined.

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Speaking at a May 20 event at Rome’s Gregorian University for the launch of a book dedicated to Benedict’s pontificate – and a day before Benedict’s Fatima statement gained so much attention – Ganswein said that the papacy “remains the foundation of the Catholic Church” but he said “the papal ministry is not the same as before.”

Benedict, he explained, “left the papal throne and yet, with the step he took on February 11, 2013, he has not abandoned this [papal] ministry.” Ganswein said quitting in that sense would have been “quite impossible after his irrevocable acceptance of the office in April 2005” when the conclave of cardinals elected Benedict pope.

Ganswein went on to say that Benedict intentionally “built a personal office with a collegial and synodal dimension, almost a communal ministry.”

Consequently, he said, there are “not two popes, but de facto an expanded ministry – with an active member and a contemplative member,” referring to Francis and Benedict.

The emeritus pope “had taken only one step to the side to make room for his successor and a new stage in the history of the papacy.”

(Elements of Ganswein’s talk were reported by various outlets but the National Catholic Register has the most complete version.)

It’s an open question as to whether Ganswein clarified or confused the concept of what the papacy is today, and in what sense there could be two popes at the same time.

But the archbishop – who, in addition to looking after Benedict, also plays a largely ceremonial role in Francis’ administration – continued to make his case. In the talk, for example, he sought to distinguish Benedict’s resignation from that of the last pope to quit the office, Celestine V.

Celestine was an elderly hermit, Pietro da Marrone, who was chosen as pope in 1294 by cardinals who had been deadlocked for two years over a successor. Celestine was overwhelmed by the job and the intrigue, and abdicated after five months, reverting to his original name.

He was imprisoned by his successor, Boniface VIII, who feared that some might rally around Celestine as an antipope; Celestine languished in jail and died in 1296.

In his speech, Ganswein said Benedict’s resignation was not akin to Celestine’s because unlike Celestine, Benedict did not return to using his baptismal name, Joseph Ratzinger, after he stepped down, nor did he stop wearing the distinctive white papal cassock.

Yet Ganswein’s assertions actually seem to run counter to some of Benedict’s own words. The pope emeritus, after much speculation about why he kept the papal title and white cassock, told an interviewer in 2014 that “there were no other clothes available” when he resigned – an explanation that many found odd, to say the least.

He also said that he wanted to be addressed as “Father Benedict” in retirement rather than “Pope Emeritus” or even “Benedict XVI,” but he said “I was too weak at that point to enforce it.”

Benedict himself has always stressed that Francis is the one legitimate pope but Ganswein’s remarkable argument for a “transformed” papacy and an “expanded ministry” with two popes working in tandem raises all manner of questions given the Catholic Church’s clear teaching on the supreme authority and central role of the pope, the successor of Saint Peter.

Indeed, from the moment Benedict stunned the Catholic world, and especially his tradition-minded allies, there was a debate over whether a pope could in fact resign, or abdicate, or retire. (Benedict himself used the term “renounce.”)

In his infirm final years, Saint John Paul II declared that such a resignation was impossible – “Did Christ come down from the cross?” he reportedly said. Ganswein seemed to be trying to thread the needle by noting that while Benedict did resign, Benedict is also in some sense still pope, or at least a pope.

Not everyone was convinced. Ganswein’s “claims that we have two popes are clearly absurd and ridiculous” tweeted Massimo Faggioli, a church historian and theologian at Villanova University.

From the other side of the spectrum, the blogger known as Augustinus, who writes for the traditionalist website Rorate Caeli, responded to Ganswein’s speech by arguing that “the idea that the papacy itself has now been transformed in its very depths, and that to effect this transformation Benedict XVI’s will and actions in February 2013 were enough, raises extremely sensitive, nay, disturbing questions about the very theology of the Church.”

Rocco Palmo, who writes a clerical insider’s blog called “Whispers in the Loggia,” called Ganswein’s model a “Papal Diarchy” — as opposed to a monarchy – a meme that was already being championed in the Italian media two years ago by fans of Benedict.

Under that reasoning, Benedict renounced the governance aspect of the papacy, but shares the other powers, and he remains in a monastery in the Vatican itself to express that shared authority.

Now, that’s a recipe for a Vatican conspiracy as big as the Third Secret of Fatima, and the flames don’t need much fanning, given how Francis has shaken conservatives.

Benedict was in fact already a rallying point for Catholics unhappy with Francis, and the retired pope’s disciples continue to launch initiatives to promote Benedict’s legacy.

Moreover, while the emeritus pope pledged to stay “hidden from the world” following his stunning resignation, he has periodically appeared at Vatican events – often at the behest of Francis, who encourages him to be a “grandfatherly” figure to the church. He also regularly speaks and writes to faithful followers to convey his views on various issues.

All of that has sparked the dry kindling of conspiracy.

Now Benedict’s own righthand man has thrown gas onto the fire, and it seems unlikely to die down anytime soon.

In his speech at the Gregorian, Ganswein expressed regret for comments he made in March describing Benedict – who was about to turn 89 – as “a candle that is slowly, serenely fading.”

That remark sent jolts of panic through many in the church, and not a few obituary writers.

Ganswein said, however, that his comment “was stupid.” Benedict, while frail, is mentally sharp, he said, and continues to receive visitors and deal with correspondence.

Ganswein also said that Benedict may make a major public appearance at the Vatican on June 29, which will mark the 65th anniversary of his ordination as a priest. “[T]his may present an opportunity to show that Benedict XVI is well,” he said.

It may also be an opportunity of touch off another round of speculation about who is really the pope, or if there are two popes.

And if that weren’t enough, the Vatican has announced that Francis (the other pope) is planning to visit Fatima next year for the centenary of the Marian apparitions.

At this point the plot lines could write themselves.