The men play dominoes with a gusto that transforms the game into a virtual contact sport, lifting the pieces high in the air before smacking them down in a percussive staccato that provides a back beat to the buzz of their conversations.
The easy camaraderie in the ramshackle cafe in this largely Christian town barely distracts from the main topic of discussion: the dramatic takeover last month of Mosul, about 10 miles to the west, by the Al Qaeda renegade faction now known as the Islamic State.
The ascendance of the Islamic State — a Sunni Muslim faction that embraces an intolerant strain of fundamentalist Islam — has generated alarm among the region's diverse minority populations, including those here in the sprawling flatlands known as the Nineveh plains. The area is home to historical settlements of Assyrian Christians, Shabaks (a mostly Shiite Muslim ethnic group with Persian origins), Shiite Turkmens and Yazidis, with roots in Zoroastrianism.
In Mosul, a mostly Sunni Muslim city, Islamic State militants reportedly gave Christians a deadline of last Friday or Saturday — accounts vary — to convert to Islam, leave the city or face death.
Most Christians are believed to have fled Mosul, long one of Iraq's principal Christian hubs. The threat is the latest blow to the dwindling Christian population in Iraq, where the faith has been present for almost 2,000 years, clerics say, brought by early disciples to the fertile plains of the Tigris and Euphrates.
"For the first time in Mosul's history, there are no services being held and the church bells are silent on Sunday," lamented William Wardeh, spokesman for the Hammurabi Human Rights Organization, a watchdog group. "This is a crime in and of itself."
In recent decades, clerics say, conflict, sectarian strife and other factors have more than halved an Iraqi Christian population that once exceeded 1 million, including various Eastern Rite sects, both Catholic and Orthodox. Many worshipers have immigrated to Europe, North America and Australia.
In Bartella, with a population of 20,000, fear of what the self-declared Islamic "caliphate" may bring has prompted a new security regimen. The town is now part of the security zone of Kurdish peshmerga forces, who moved into this and other disputed territories in the wake of the Islamic State's lightning advance last month. Residents have set up checkpoints at the town entrances and reactivated a local militia. Strangers are eyed warily and asked for identification.
"People are afraid, and we don't know what to do," said Father Banham Lalo, pastor of St. George Church, one of three churches in Bartella.
During the U.S. occupation of 2003-11, Sunni insurgents regularly targeted Iraqi Christians and their churches, viewing them as sympathizers of Western "crusader" forces. Churches were bombed and clerics executed, prompting many Christians to leave Iraq and raising fears about their future here.
"It's important that Christians stay in this part of the world," said a 31-year-old local militia volunteer, who asked to be identified only as Kyriakos for security reasons.
In historical terms, clerics say, the peril is nothing new. Successive waves of marauders and invaders have sacked the town and persecuted its Christian inhabitants.
"Bartella was razed to the ground three times," said Lalo, noting that the current site was rebuilt atop ancient ruins. "When you walk near areas of Old Town, you are actually walking on the rooftops of buildings."
Said to have been a rest stop for St. Thomas on his passage to India, Bartella in its golden age was an economic powerhouse, renowned for its markets and verdant orchards that gave the town its name, an Aramaic word that means "Place of Trees."
Although Christianity was officially recorded here in the 4th century, Lalo said the oldest church in the area was built in AD 200.
During the 1980s, Iraqi leader Saddam Hussein's "Arabization" projects appropriated farmland from Assyrian Christians and handed it to families of soldiers and officers for housing. Over time, agriculture went into decline and many Christians left.
Despite the tense security situation, the most immediate issue confronting residents of the Nineveh plains is a lack of running water and electricity. The conflict has led to more power outages in much of northern Iraq.
The shutdown has silenced the sesame-paste workshop of the Matti family, ordinarily a cacophony of milling, washing, pouring, roasting. The final grinding turns sesame seeds into the thick, beige tahini paste known as rashi.
The patriarch of the family, Khadher Matti, doesn't seem to mind the stoppage. A man of 80 who learned to make rashi from his father and grandfather ("we used to use a donkey to grind the seeds"), he seems unperturbed by the present turmoil.
"Rashi is too hearty for summertime consumption anyway," he said.
Many worry that the emergence of the Islamic State and its intolerance for religious diversity could be the death knell for the faithful. Across the region, Christian clerics have been pleading with their co-religionists not to abandon the region, but the rise of hard-line Islamist factions seems sure to accelerate the exodus.
Lalo, however, said he has no intention of leaving.
"If I go to Sweden or America, I lose my identity," he said. "Our value comes from us being rooted here."
Bulos is a special correspondent. Times staff writer Patrick J. McDonnell in Irbil, Iraq, contributed to this report.