Eyes were riveted once again Wednesday on a simple chimney pipe rising above a sublime Renaissance chapel after Catholic cardinals failed to elect a new leader for their 1.2 billion-strong Church in three ballots.
The 115 cardinals kicked off their conclave in the Sistine Chapel on Tuesday to find a successor to Benedict XVI, who brought a troubled eight-year papacy to an abrupt end by resigning last month aged 85.
The chimney disgorged black smoke after Wednesday's first two voting sessions and after Tuesday's first ballot, indicating that no one had gained the two-thirds majority needed to become the 266th pope.
A successful result would be signalled immediately by white smoke and followed soon afterwards with the famous announcement in Latin, "Habemus Papam" (We Have a Pope).
The failed ballots deepened the suspense as no clear frontrunner has emerged, although conjecture has coalesced around three favourites: Italy's Angelo Scola, Brazil's Odilo Scherer and Canada's Marc Ouellet, all conservatives like Benedict.
Some analysts suggest that Benedict's dramatic act—the first papal resignation in over 700 years—could push the cardinals to take an equally unusual decision and that an outsider could emerge as a compromise candidate.
Hopes are high in the Philippines for the popular archbishop of Manila, Luis Antonio Tagle, and on the African continent for South Africa's Wilfrid Napier, the archbishop of Durban, but in practice their chances are slim.
Whatever hopes Vienna Archbishop Christoph Schoenborn may have, his mother did him no favours by telling the Austrian press that the job of pope "would be much too difficult" for him.
US President Barack Obama also chimed in on Wednesday, saying an American pope could be just as effective as any other, before quipping: "But the (US) conference of Catholic bishops ... don't seem to be taking orders from me."
Two-thirds of the cardinals are from Europe and North America, and the view among many experts is that only someone with experience of its inner workings can reform the scandal-tainted Vatican bureaucracy, the Roman Curia.
All the "Princes of the Church" were appointed by Benedict or his predecessor and ideological soulmate John Paul II.
Tens of thousands of people gathered in a rainy St Peter's Square on Wednesday, huddled under umbrellas to gaze up at the chimney pipe for the only information obtainable from the secret voting conclave.
"There's a great atmosphere, we're not just waiting for white smoke, we're waiting to see a leader emerge who can open up the Church to the modern world," said Jean Chiche, who had come with his wife and daughter from Paris.
The scandal of sexual abuse of children by paedophile priests going back decades—and the cover-up of their actions by senior prelates—has also cast a long shadow on the Church.
The US group SNAP (Survivors Network of those Abused by Priests) called for over a dozen cardinals to be excluded from the conclave either for covering up abuses or making tactless remarks about the scandals.
The Vatican on Wednesday defended the cardinals and accused SNAP and other activists of showing "negative prejudices".
"None of us are surprised that they have tried to take advantage of these days to repeat their accusations and give them greater resonance," Lombardi said.
"These cardinals should be respected and have every right to be in the conclave," he said.
The main target of the criticism has been US cardinal Roger Mahony, the disgraced former archbishop of Los Angeles, who is accused of protecting predator priests for decades.
"Cardinal Mahony and the other cardinals accused by SNAP have given their answers, their explanations," Lombardi said.
Modern-day conclaves normally last no more than a few days. Benedict's election in 2005 following the death of John Paul II took just two days.
Cardinal Timothy Dolan of Boston was quoted by ABC News as saying in a letter to his archdiocese that he predicted a result by Thursday at the latest.
Vatican spokesman Federico Lombardi said the idea that a special mass to inaugurate a new pope could take place on Tuesday, the feast day of St Joseph, patron of the Universal Church, was a "good hypothesis".
In St Peter's Square, Elizabeth Carter from Wales said she was glad the electors were not rushing their decision.
"It can't be easy to decide who has the qualities needed to face today's challenges: who is strong enough to tackle sex abuse? Who can clean up the Church's image and make us proud to be Catholic again?" the 34-year-old asked.
Also Wednesday, Lombardi said the cardinals, whose average age is 72, should be allowed to smoke and drink wine, within reason, at their Santa Marta residence a stone's throw away from the Sistine Chapel.
"We would hope that they are doing that reasonably and taking care of their health," he said, adding that since "wine is part of a normal meal here in Rome, I would expect that it would be on the menu. They are free to drink if they wish."