There's nothing extraordinary about the way the students at Machon Miriam's conversion class are engaged in afternoon prayer. Ditto for their modest dress, their humble demeanor and their intense focus on the lesson about Jewish customs their instructor is teaching. Yet Ra'anana Birnbaum, who oversees the Machon Miriam ulpan, insists, "This is a very special, very unusual ulpan." What is special here isn't something you can see. It is, however, something you can hear. What is so unusual about these students is revealed in their native tongues of Spanish and Portuguese. The dozens of people gathered in Machon Miriam's classrooms in Heichal Shlomo, adjacent to Jerusalem's Great Synagogue, have come from Costa Rica, Chile, Argentina, Brazil, Uruguay, Colombia, Palma de Mallorca, Portugal, Spain, Bolivia and Peru. One couple, Birnbaum says, has come from the farthest reaches of the Amazon. Among them are people like Adriana, a Roman Catholic from Colombia who met her Jewish fiancÃ© in London and has moved with him to Israel; and Gisella, the daughter of a Jewish man and Catholic woman who has left Argentina to "find herself" in Jerusalem. Many, many more are like Agison and Jerusa, two Bnei Anusim (descendants of Iberian Jews who were forced to convert to Christianity during the Inquisition) from Brazil. Agison first met Jerusa on a bus, making eyes at her "like in a soap opera." And like a mindbending soap opera plot twist, the two happened to share family secrets of converso lineage. Agison's grandparents had come from Portugal and maintained unusual, non-Catholic practices that he would later realize were Jewish customs. Although her father was Catholic, Jerusa's mother steadfastly refused to go to church, part of a set of rules her own mother had established. By the time they met, Agison and Jerusa knew they were Jewish. She wanted to live openly as Jews, but Agison was hesitant. "It took two years of marriage for me to convince him," Jerusa says, as her husband smiles sheepishly. The decision was not a simple one. It was easier said than done. Their town had Jews, but they were secular, and could not teach the couple much. There was no synagogue to provide communal prayer. So they made do as best they could, following the Bible. Literally. Without the benefit of knowledge of Jewish tradition, the couple improvised. For Pessah, they meticulously removed all hametz from their home. They made fresh grape juice, slaughtered sheep and - without knowing exactly how they were supposed to - baked their own matzot. They went to the fields to count the omer. On Succot, Agison wanted to gather for himself the four species, but he wasn't sure which species to collect. For a mikve, Jerusa would travel to a secluded beach near Rio de Janeiro. And so it went for them. It took seven years to get their hands on Jewish books in Portuguese. Eventually they learned about various halachot. While still in Brazil, the 30-something couple and their young children underwent conversion through the Conservative movement. They made aliya last year - not as Agison and Jerusa, but as Eliahu and Rivka. The changes have been extreme. Whereas in Brazil Eliahu owned a successful business selling packing materials, today he works in maintenance. His wife works as a babysitter. "We didn't come here for a more lucrative lifestyle," he says, knowing the suspicion with which Israelis often regard strangers. Instead, they say, they came for experiences like their first traditional Seder, held in their spartan apartment in the Beit Canada absorption center in southeast Jerusalem. And although they are citizens and already recognized by the Interior Ministry as Jews, they are undergoing an Orthodox conversion now because they believe that only it is valid. "We came to seek God," Eliahu says. "And so far, things are working out." Birnbaum, who is translating the narrative, beams with pride for her students. "Here we have a human fabric that knows practically no bounds," she says. THE ULPAN is connected to Shavei Israel, an organization founded by Michael Freund that has become well known in recent years for locating, educating and bringing here thousands of people around the world with previously unlooked-for historic ties to the Jewish people. Freund, who investigated the issue of anusim (who are also known by the derogatory terms marranos and chuetas, or less offensively as conversos) and inspired the Chief Rabbinate to take an interest in it as well, calls the Machon Miriam program "the best revenge against the inquisitors." But Freund and Birnbaum both know that the historical mysteries inherent in the survival of the Bnei Anusim, and the economic hardship prevalent in many countries where they live, make "faking it" an attractive option for those who do not actually have Jewish heritage. Both say they are very careful to weed out impostors. "We are very sensitive to those who may have Jewish roots," Birnbaum says. "At the same time, however, we are very careful not to be exploited by those with illegitimate claims, who merely wish to come to Israel for a better life. "I know these people," she adds. "I'm Latin myself." Although she was born and raised in Jerusalem, she spent several years in Uruguay with her husband, Rabbi Eliahu Birnbaum, who served as chief rabbi of the country. Birnbaum's father also served as chief rabbi of Uruguay for many years. "I can tell after 10-20 minutes whether someone is telling the truth about these things," she says, speaking in the rapid-fire cadence common to many Spanish speakers. "I have been told by one woman who wanted to join our class - a devout Christian - that she just wanted to bring her mother and sister to live out the rest of their days in Israel. That's why I understand, as well, the strictness of the Interior Ministry and the Rabbinate. There's no end to the people who apply." At the same time, Birnbaum says, "I see how those who are honest and sincere only become more serious [about the classes] all the time. Listen, this is a difficult process. It's a year of bonding with a community, of coming to class twice a week, seven hours at a time... someone who comes to this ulpan with ulterior motives won't be able to stand it." Moreover, Birnbaum continues, "It doesn't matter to me why a person comes to convert. It doesn't matter to me whether he comes because he has fallen in love with a Jew, or whether he has fallen in love with the Jewish people as a whole. What matters to me is that, as soon as he has made that decision to convert, that he undergoes the process with a sincere desire." GISELLA'S DESIRE, says the shy 22-year-old from Argentina, is to "seek myself, to find an identity." That has been a painful process so far for Gisella, who made aliya in 2003. The child of a Jewish father and a Catholic mother, she has been wrestling since an early age with the question, "Who am I?" First, Gisella went to public school. Then she was sent to a private school that taught both Catholic and Jewish children. Feeling part of neither crowd, she hung out with a small group of kids who considered themselves atheists. Eventually, in a bid to "fit in," Gisella started to take lessons in Christianity with the Catholic kids, but they wouldn't speak to her. So, Gisella went back to public school. There, a strange thing happened when the drama class prepared a presentation of the movie Sister Act, in which Whoopi Goldberg impersonates a nun. "My father absolutely refused to allow me to take part in this," Gisella says. "He had never made much of a big deal about his being Jewish, but all of a sudden, the idea of his daughter dressed up as a nun made him very upset." The incident also compelled Gisella to explore what Judaism meant to her. After high school, she came to Israel. Once again, she doesn't quite belong in any particular crowd. "Growing up, I suffered because of my Jewish name," she says. "Now in Israel, I am treated as a non-Jew. When people hear that I am converting, they start testing my knowledge of Judaism. Some people say, 'What, are you looking for more money in Israel?' "I've learned to be inconspicuous about my past. It's easier for me that way." Gisella, however, is finding her way. She has a job in telemarketing and is studying for her psychometric exams. She has a boyfriend ("He's religious," she notes) who is helping her through the conversion process. More than a few times, Gisella thought of going back to Argentina. Her parents, though, encouraged her to stay here. "They know," she says, "that there is something here that I need." THE TRANSITION from Spanish-speaking outsider to Hebrew-speaking Israeli immigrant is a complicated one. The Machon Miriam staff tries to make that transition as smooth as possible. "When someone comes to us," says Birnbaum, "I ask, 'Do you have a community? Do you have an adoptive family?' If not, we provide them with one. We have a network of graduates who support and guide the students on their path to a new life. They have connections to communities, to rabbis, to synagogues. We make sure students find jobs. There's a lot of 'togetherness' here." There is also, she says, a focus on more than just basic knowledge of Bible stories. "My approach is that conversion is a cultural transformation as well as a religious one, so students need to learn about everything - about society, about history, about culture, about Halacha, about faith and dogma. That's why this is such a broad curriculum. "For example, when they walk down the street, the students see so many different modes of dress, just within the religious community - many different kinds of kippot, so many different kinds of women's head coverings. There are cultural codes to understand. So we teach them the history of the Jewish people, we teach them Hebrew literature... but we also teach them about these Jewish cultural cues." All these elements, Birnbaum says, add up to success. When the ulpan's graduates stand before the Chief Rabbinate's conversion court judges, she says, "they are so well prepared that 99 percent of them pass their tests. I can count on my hands the number of students who, over the years, haven't passed." The connection does not end there, however. Graduates are welcome, even encouraged, to hold their weddings and bar and bat mitzva celebrations at the ulpan. The organization's social network is mobilized to ensure that new converts aren't simply thrown into their new surroundings. "You have to remember," Birnbaum says, "that the conversion process is difficult even after the conversion itself. You're in a state of euphoria. Your whole life has changed. But everyone sees you as the same person they knew yesterday. Work doesn't just fall from the sky, nor does a spouse, nor do friends. "There's always an emotional let-down after conversion. So we always try to guide them through it, and beyond. Converts need to acclimate to life after the conversion. It may sound very easy to someone who doesn't understand it, but it can be very hard." The current class is Machon Miriam's ninth. Overall, about 500 students have finished the course. The surface, Birnbaum says, has just begun to be scratched. "We have a full class right now, and there are more people waiting to get in. There's never a situation where our classrooms aren't full to bursting."