For those who believe, the devotion is real. Tears stream down the cheeks of 2,000 men ripe for the return of the Mahdi, the 12th Imam they expect will soon emerge to bring justice and peace to a corrupt world.
Eyes stare upward and arms open wide to receive God's promised salvation. The storyteller's lyrical song speaks of tragedy on the path to salvation, prompting cries of anguish and joy.
As at a Christian revivalist meeting that promises healing and redemption, many weep as they pray for the Shiite Muslim version of the second coming of the Messiah. "Sometimes I feel they don't need me," says Mahdi Salashur, the religious storyteller, after leading congregants on an emotional late-night journey. "They are wired to God in their hearts."
Among the true believers is Iran's hard-line President Mahmoud Ahmadinejad, who predicted with "no doubt" his June election victory, months in advance, at a time when polls gave him barely 1 percent support. The president also spoke of an aura that wreathed him throughout his controversial UN speech in September.
"O mighty Lord," Mr. Ahmadinejad intoned to his surprised audience, "I pray to you to hasten the emergence of your last repository, the promised one, that perfect and pure human being, the one that will fill this world with justice and peace."
Later, at a private meeting with a cleric that was caught on video, Ahmadinejad shared his views of the moment. "I felt that all of a sudden the atmosphere changed, and for 27 to 28 minutes the leaders did not blink," he said. "They were astonished.... it had opened their eyes and ears for the message of the Islamic Republic."
A spokesman last week dismissed the video as fake (other sources confirm it is authentic), and denied that Ahmadinejad bases decisions on "heavenly affairs." But this presidential obsession with the Mahdaviat [belief in the second coming] yields a certitude that leaves little room for compromise.
From redressing the gulf between rich and poor in Iran, to challenging the United States and Israel and enhancing Iran's power with nuclear programs, every issue is designed to lay the foundation for the Mahdi's return.
Ahmadinejad's executive self-confidence contrasts sharply with the eight-year presidency of Mohammad Khatami, a moderate cleric who advocated a "dialogue of civilizations" and Iran's return to the international fold.
Ahmadinejad is instead transporting Iran back to the first radical years after the 1979 Islamic revolution, defined by battling imperial US and Soviet powers and Zionism. The former Revolutionary Guardsman says Israel is a "tumor" that must be "wiped off the map." He denies the Holocaust. And he is pushing the Iran's nuclear-power card; stalled talks with the European Union to curb those plans resume Wednesday in Vienna.
"This kind of mentality makes you very strong," says Amir Mohebian, political editor of the conservative Resalat newspaper.
"Bush said: 'God said to me, attack Afghanistan and attack Iraq.' The mentality of Mr. Bush and Mr. Ahmadinejad is the same here - both think God tells them what to do," says Mr. Mohebian, noting that end-of-time beliefs have similar roots in Christian and Muslim theology.
"If you think these are the last days of the world, and Jesus will come [again], this idea will change all your relations," says Mohebian. "If I think the Mahdi will come in two, three, or four years, why should I be soft? Now is the time to stand strong, to be hard."
That mind-set also hearkens back to the missionary ambition of the newly forged Islamic Republic. "What Ahmadinejad believes is that we have to create a model state based on ... Islamic democracy - to be given to the world," says Hamidreza Taraghi, head of the conservative Islamic Coalition Society. "The ... government accepts this role for themselves."
Any possibility of détente with the US may also be in jeopardy, if the US-Iran conflict is cast in Mahdaviat terms. That view holds that the US - with quasireligious declarations of transforming the Middle East with democracy and justice, deploying military forces across the region, and developing a new generation of nuclear weapons - is arrogantly trying to assume the role of Mahdi.
A top priority of Ahmadinejad is "to challenge America, which is trying to impose itself as the final salvation of the human being, and insert its unjust state [in the region]," says Mr. Taraghi.
Taraghi says the US is "trying to place itself as the new Mahdi." This may mean no peace with Iran, he adds, "unless America changes its hegemonic ... thinking, doesn't use nuclear weapons, [or] impose its will on other nations."
Final rulings on such issues rest with Supreme Leader Ayatollah Ali Khamenei, whose position of velayat-e-faqih - God's jurisprudent on earth - is meant to serve as the direct link with the divine.
And while rule by clerics might suggest joy over a leader who believes he is divinely guided, Shiite religious texts ban all claims of such revelations and warn against "false prophets." The punishment for "fooling" people is so great, notes one, that "hell's fire and its occupants are crying."
Analysts say a lay president who demonstrates such a connection may also be a danger by undermining the role and authority of Ayatollah Khamenei.
"One objection [to the government] is they take advantage of Islamic religion and Imam Zaman [Mahdi] - they exploit them," says Grand Ayatollah Hossein Ali Montazeri, a ranking dissident cleric in Qom. "If the government uses religious slogans and religion as a tool [to gain power], this makes people fed up with religion and is wrong."
The Mahdi's eventual return is an article of faith for Shiite Muslims that taps deeply into Persian consciousness and mystical tradition. Signs began to appear in Tehran three years ago, announcing that "He's Coming." But only a portion of Iranians actively prepare for that moment.
Part of the tradition holds that the Jamkaran mosque was ordered built by the Mahdi himself, during a dream revealed to a "righteous man" some 1,000 years ago. It is here that believers are closest to the Mahdi. Written prayers dropped into the adjacent well (which, local guides point out has no religious basis) are thought by pilgrims to be divinely answered.
Officials deny rumors that Ahmadinejad, as mayor last year, secretly tasked the Tehran City Council with reconfiguring the capital to prepare a suitable route for the Mahdi's return. They also deny that a list of Ahmadinejad's new cabinet members has been dropped into the well - a superstition that even Ayatollah Khomeini, the father of Iran's revolution, refused to associate with.
"The legitimacy of Khatami came from the religious elite. But the legitimacy of Ahmadinejad comes from traditional religious thought [over half a century ago]," says Mohsen Kadivar, a reformist cleric and philosophy professor in Tehran. "Ahmadinejad and his men believe it is popular, [but] it's a very simple interpretation. We don't believe in it; the majority of academics don't believe in it."
Still, an early cabinet decision earmarked $17 million for Jamkaran. And there is talk of building a direct train link from Tehran to the elegant blue-tiled mosque, which lies 65 miles south of the capital, east of the Shiite religious center of Qom.
Already, Jamkaran is estimated to receive the second-largest number of pilgrims of any holy site in Iran. Devotees, many from Iran's legions of poor and less-educated who voted heartily for Ahmadinejad, line up by the hundreds to receive food, and on Tuesday night settle in family groups on blankets outside.
With hands over their hearts in supplication, they approach the radiant mosque for evening prayers, and scrawl requests to the Mahdi on preprinted prayer forms. Many pilgrims say their prayers are answered, and health problems are healed.
"When you come here, you get your [prayer] request fulfilled, if you are clean and pure," says Fatima, speaking through a small gap in her head covering as she tends to a pot of rice boiling on a portable gas stove. Her family is holding vigil outside the mosque after dark.
She attributes a significant healing 10 years ago to a Jamkaran visit, but says the "Mahdi does not allow me to talk about it with anybody else."
Pilgrims are not limited to the poor or infirm, however. One young couple - he's a banker in Qom, and wears a stylish suit - say they had their prayer answered after coming 40 Tuesday nights in a row. Now they have another request, and will be here 40 times again.
"We Iranians have very strong beliefs, and this is a holy place," says Mahdi Abdulahi, holding a late-model motorcycle helmet as he stands near the mosque entrance. "I don't think it's a matter of [presidential] propaganda to crank you up. It depends upon your own belief."
Critics, many of them clerics, accuse Ahmadinejad of manipulating public sentiment, even if he is personally sincere in his belief.
"They pay more attention to the facade of religion, rather than the jewel of religion," says Mohammad Ali Ayazi, a professor at the influential seminary in Qom. "Having sincerity or honesty does not make any difference to the results.
"It's very dangerous, a person exploiting religion for political achievement, because everyone has their own relationship with God," says Mr. Ayazi, who estimates that focus on the Mahdi's imminent return appeals to 20 percent of Iranians. "It makes me sad that someone would endanger that."
Ayazi says that Ahmadinejad uses religion to motivate the public because he lacks political legitimacy. "You don't expect such a thing from a leader, because it turns comic. You laugh, but you become sad, because it is not supposed to be funny."
Sayed Hadi Hashemi, a black-turbaned senior cleric in Qom, says that "The Mahdi will rise, and it's a reality that needs [study] by religious science. But if you say, as Ahmadinejad says, 'We should construct an avenue in Tehran for the Mahdi to arrive,' this is only fooling the public."
But few doubt the sincerity of Ahmadinejad's belief. Some point to his seemingly impossible prediction of electoral success, three months before the June vote.
"You will see, on the day of the election, I will be the winner - I have no doubt about it," says political editor Mohebian, quoting those who heard the remarks. "People change, and we can calculate [politically] why he won. But this [gives a] kind of self-confidence," he says. "Mr. Ahmadinejad thinks he has a mission."
Even as the last lilting note of the night fades, burly guards surround the religious storyteller, linking arms to protect him - not from assassination, but adulation.
As the Madoh - a Shiite Muslim storyteller - rises from a sea of red-eyed, kneeling men at the Jamkaran Mosque, devotees surge forward to try to hug, kiss, or touch him.
Later, like a rock star leaving a backstage exit, Mahdi Salashur puts on a basiji militia jacket, pulls the hood over his head in semidisguise, and steps out the door.
For the previous two hours, he has relentlessly rallied his listeners around the belief in the Mahdi, the all-powerful 12th Imam, whom Shiites expect to return to earth.
"Don't let the wish stay in our hearts! Come on, come on! I have a fear of not seeing You!" Mr. Salashur tells the crowd in a poetic, longing voice. "Everybody wants to see the Lord and Master of the Age! Mourn, raise your hands."
People chant. Men cry.
"Those who sinned, cry more!" orders the Madoh.
Salashur's voice steadies as he tells a story of a faithful friend "martyred" during the Iran-Iraq war of the 1980s. The friend dreamed that Imam Hossein, who was killed in battle in the 7th century, appeared and said he would take him away.
"The night before he becomes a martyr, he was crying," Salashur recalls, raising the emotional heat. His friend worried that he was not "pure enough" to stand before the martyrs.
"If they ask: 'How do you justify yourself?' I have no answer," Salashur quoted his friend saying. That night, he was killed.
"Yah, Imam of the Age! I ask you to swear, whom [do] you love more?" says Salashur, sitting quietly with hands folded, his voice choking.
Then, imploring: "For Heaven's sake, take us away in a way that we can look at your eyes [without shame]!"
The Madoh cools the crowd with a lengthy standard prayer, the Tavasol, and then begins more stories. One is of Zeinab, aunt of the Imam, when she entered Damascus.
"Aye, cry! Love your own crying!" Salashur cringes, before he even starts. "Akhh, [it is so bad] I want to die! I want to die!"
"They wanted to pour flowers on the head of Zeinab," he says, as the crowd approaches meltdown. "Yah Imam of the Age, our apologies! All of a sudden, people were throwing stones at Zeinab from the top of the buildings..."
The audience bursts, and wails as if at a funeral. The Madoh cries out in God's name, again and again.