At midnight on April 18, bells throughout the cathedrals and sanctuaries of the Orthodox Christian world will toll, devout Christians will cross themselves and rush to kiss holy icons as priests chant "Christ has risen" and mark the beginning of the holiest day of the Orthodox calendar.
April 19 is Easter, celebrated with centuries-old rituals marking the story of the resurrection of Jesus Christ.
This year, it's different.
For epidemiologists and medical experts, the holiday is potentially shaping up to be a critical moment for curtailing -- or the opposite, fueling -- the spread of the pandemic that is wreaking havoc across the globe.
Just as many governments have struggled to respond to the infection, Orthodox leaders across the former Soviet Union and Eastern Europe have also struggled, trying to balance the exacting demands of religious rituals with the realities of medical science.
A week earlier, Roman Catholicism and most Protestant denominations marked their Easter holidays with televised services, and shuttered churches. At the Vatican, Pope Francis broke with centuries of tradition by celebrating Easter Sunday mass on April 13 via livestream from a nearly empty St. Peter's Basilica.
In Orthodoxy's largest denomination, in Russia, church leaders hesitated to impose restrictions as the coronavirus danger built in February and March, and in some cases gave conflicting guidance.
St. Petersburg church officials on March 26 announced a ban on parishioners from attending services, but that was then overruled by the Russian Orthodox Church's headquarters in Moscow.
The Russian church also moved weeks ago to impose stricter hygiene measures: for example, restricting people from kissing holy icons or from reusing a special communion spoon used to give people sanctified wine.
But some local priests have spurned the advice, both from public health workers and from their church superiors.
On March 29, Patriarch Kirill, the head of the Russian church, publicly urged believers to "strictly obey the regulations imposed by the health authorities," refraining from physically going to church, and not to listen to priests who opposed social-distancing and self-isolation measures.
He also cited the unusual example of a 4th-century prostitute, now a saint, who sought to pray in a church in Jerusalem but was blocked as if by some unseen force. According to legend, the woman managed to enter after praying before an icon of Jesus's mother, Mary, and then spent years wandering in the desert.
"That's exactly how we should live now. And do not listen to other kinds of sermons, including those coming from unreasonable clergy. Listen to what the patriarch told you today," Kirill said. "And not just from myself: from the great ascetic feat of the holy Reverend Mary of Egypt, who saved the body and soul by going into the desert, in complete isolation from the people around her."
For Orthodox Easter, leaders have called for people to stay home to pray, and not go to churches during Easter services, which typically include people staying up all night and praying as part of the ritual known as the Easter Vigil.
Local governments and local church leaders also plan on televising Easter services from parishes around the country, according to officials.
And a survey conducted by the state-funded Public Opinion Foundation, published April 17, found that a majority of Russians believed that Easter services should be held this year without parishioners.
Still, as many as 43 of Russia's 89 regions expect to have church buildings open to parishioners on April 18, Easter eve, the newspaper RBC reported.
As of April 18, Russia had reported more than 36,000 confirmed coronavirus cases, and 313 deaths. There are suspicions that the official figures are lower than the real ones, and Moscow's mayor suggested days earlier that the country was just at the beginning of a steep upward trajectory for infections.
In Ukraine, the situation is complicated by the existence of rival Orthodox Christian churches.
Metropolitan Onufriy, leader of the Ukrainian Orthodox branch that is affiliated with Moscow, echoed the Russian church leaders, calling on people to stay home and watch Easter services on TV.
But Onufriy also said that those who wanted attend services in person could come and pray outside church buildings as long as they maintained distance from one another.
That brought a rebuke from Orthodox Church of Ukraine, which formally broke away from the Moscow Patriarchate and was recognized as fully independent last year.
It is "a Christian duty" to stay home during the pandemic, Metropolitan Epifaniy said in an interview with RFE/RL's Ukrainian Service.
Adding further to the drama: an outbreak of coronavirus cases at the 1,000-year-old KyIv Pechersk Lavra, a labyrinthine monastery complex built into the hillside overlooking the Dnipro River.
City officials this week sealed off the famed monastery, which is controlled by the Moscow Patriarchate-affiliated church, after two priests died of the disease, and dozens were infected.
Ukraine had reported more than 5,100 confirmed coronavirus cases as of April 18, including 133 deaths.
In Georgia, where the local Orthodox Church plays an outsized role in the country's social and political life, priests have been at the forefront of unscientific efforts to stop the spread of disease.
Last month, a convoy of clergy drove through the capital Tbilisi, sprinkling holy water on drivers and brandishing icons in an effort to bless the city and protect it from the coronavirus.
Earlier this week, after reportedly tense negotiations with political leaders and public health officials, church leaders were permitted to allow parishioners to attend dusk-to-dawn Easter vigil services despite a curfew and other restrictions imposed on Tbilisi and elsewhere.
Under the agreement, worshippers will be allowed to attend services in large cathedrals, provided they maintain a distance of 2 meters. Those who attend small churches are to remain outside their church building.
The agreement also says parishioners should arrive for the services before 9 p.m. and leave after 6 a.m.
Church spokesman Andria Jagmaidze said the measures would ensure services would continue, while complying with public health recommendations. He said nothing, however, about the communal spoon used for communion
Georgia had reported 370 coronavirus cases and three deaths as of April 18, according to the Johns Hopkins University database.
Mirian Gamrekalshvili, а Georgian theology researcher currently based in Munich, told RFE/RL that there were notable differences in how the different countries' churches have handled the coronavirus epidemic.
Georgian church leaders have taken the approach that the country is somehow special or protected, and therefore strict measures aren't necessary.
"They're ignoring the virus, and its dangers," he said. "They say: 'If a person is a believer, if they believe in God, then the virus won't be dangerous for them.'"
Making matters worse, he said, is that many medical workers take their cues from church leaders, and can't, or won't, push for harsher restrictions.
"The worst is yet to come" in Georgia, Gamrekalshvili said.