It’s a Thursday afternoon in April and Rukmini Callimachi, a reporter for The New York Times, has just filed a story from midtown Manhattan with two colleagues about a terrorist attack in Garissa, Kenya, where Somali militants stormed a university and killed 147 people. Because she is on the terrorism beat, her stories cover the world, from the scrubland of northern Nigeria to the offices of Charlie Hebdo in Paris. She is one of the few New York-based reporters at the Times to hold the title “foreign correspondent.”

The Kenya article spreads quickly on Twitter, generating screens full of comments on her iPhone from her more than 17,000 followers. For Callimachi, Twitter is not merely a platform from which she can broadcast her work; it is also a conduit through which she can acquire sources. Since she joined the Times in March 2014, Callimachi’s has become a regular front-page byline, thanks in part to the scoops she has scored through her cultivation of extremist contacts online, including people affiliated with Al Qaeda and the Islamic State. “They’re not hard to find,” she says of jihadist profiles on Twitter. “It’s the dude on the horse with the sword that’s dripping with blood.” 

Callimachi’s reporting had recently taken her to Washington state, where she interviewed a teenage girl who almost joined the Islamic State. Arrayed in her cubicle in the Times’ airy third-floor newsroom are some of the documents an Islamist recruiter sent the girl: an illustrated children’s book about the Koran, a paperback on the Islamic dress code for women, a 12th birthday card. The resulting story sounds signature Callimachi: finely wrought, newsy and meticulously reported. In other words, Pulitzer bait. 

Callimachi has been named a finalist for the Pulitzer Prize twice, and earlier this year she won a George Polk Award, one of journalism’s highest honors, for her reporting on the millions of dollars in ransoms that European governments secretly paid to free hostages taken by the Islamic State. “There can be no doubt that she’s one of the finest foreign correspondents of her generation, as clichéd as that sounds,” says Lydia Polgreen, Callimachi’s editor at the Times. “She’s well on her way to producing what will be a historic body of work in our profession.”

Born in communist Romania, Callimachi was just 5 years old when her family fled the country under the false pretense of visiting a dying godfather. The family moved to Switzerland before settling in Ojai, California, where she arrived speaking only Romanian and French. Even today, she says, “I approach the English language with a lot of wonder.”

At Dartmouth, Callimachi squeezed English classes into her premed course load. A notice posted in the English department her freshman year advertised an intriguing study-abroad opportunity: a summer poetry program at a castle in the Italian Alps. She went, putting an end to her medical school ambitions. The castle was owned by Ezra Pound’s daughter, Mary de Rachewiltz, who would transfix students with dramatic readings of her father’s poems and stories about his life. In Pound’s literary theories Callimachi found lessons she would later apply to journalism. “He specifically talks about the use of images—how an image in words becomes the backbone of a poem,” she says. “To me, journalism is that. You’re taking people through scenes into something that is often very far away from them.” She adds, laughing: “I don’t often talk about it, because I think most journalists would be a little freaked out.”

Her jihadi contacts have acquired a begrudging respect for her, gained through a commitment to accuracy.

During her senior year Callimachi, then vice president of the Student Assembly, became its accidental president after a classmate resigned from the top post. She focused her tenure on combating sexual assault, but realized that activism was not her calling. “It was so much work and you never got anything done,” she says.

Journalism, she eventually found, had a far greater impact, although her route to that profession would be circuitous. After leaving Hanover, she headed to Oxford for graduate programs in linguistics and Sanskrit. In 2001, she was studying the language in Delhi, India, when a 7.7-magnitude earthquake struck the state of Gujarat. Impulsively, she booked a seat on a flight headed to the epicenter and began observing the wreckage and interviewing survivors. The result was her first clip, a Time magazine dispatch that ran under someone else’s byline but gave her a “reported by” credit at the bottom.

Intent on becoming a foreign correspondent, Callimachi asked David Herszenhorn ’94—then, as now, a reporter at The New York Times—for career advice. The news was a letdown. “I’ll never forget: He said, ‘I’ve been chasing fire engines for the past five years,’” Callimachi recalls. Still, she applied for positions at the top 100 U.S. newspapers by circulation, and one—The Daily Herald, in Arlington Heights, Illinois—hired her as an intern. So began two years of paying her dues. She covered city council meetings and Christmas-tree-lighting ceremonies. “At the time I thought my life was over,” she says. At lunch she and a work friend would ask, “How do we get out of here?”

Callimachi eventually did get out of Arlington Heights, moving in 2003 to the Associated Press bureau in Portland, Oregon. She worked the night shift, reporting lottery numbers and updates on the salmon-catch quota. Once again a natural disaster would alter the course of her career. When Hurricane Katrina hit the Gulf coast in August 2005, Callimachi was stuck in Portland as stories about it by the AP’s top correspondents moved across the wire. As the months went on and the chaos in New Orleans continued, the AP was cycling through reporters to cover it. Even though her bureau chief told her that headquarters would have no need for relatively new reporters on a national story such as Katrina, Callimachi sent an email expressing interest—and was almost immediately on her way to Louisiana. There, Callimachi cataloged New Orleans’ long recovery. In one memorable article, “Katrina’s Nameless Dead,” she tracked down the names of two elderly brothers whose bodies the coroner could not identify.

Driving home from work one day in New Orleans in 2006, she saw a message on her phone about an opening at the AP’s bureau in India, a country to which she had long hoped to return. She pulled over and said a prayer. Eager to make a good impression on the bureau chief, she took a vacation and flew to India on her own dime, only to learn that the position had been filled while she was on the flight. But the bureau chief put her on a conference call with the West Africa bureau chief, who was looking for a correspondent. She got the job. 

From her perch in Dakar, Senegal, Callimachi was responsible for gathering news from 20 countries in West and Central Africa. Polgreen, who was then the Times’ West Africa correspondent, recalls reading with envy a Callimachi dispatch on a chain of islands in Guinea-Bissau where women, not men, choose their spouses. “As a competitor, I thought, ‘How did she find this story?’ ” Another journalist in the region, who declined to be named lest his employer catch him praising a competitor, revealed Callimachi’s secret: “She has no sense of shame or shyness.” By 2009—when Callimachi earned her first Pulitzer Prize nomination, for an investigation into child exploitation in West Africa—she liked the region so much that she turned down an offer from the AP to send her to India.

The biggest story in West Africa during Callimachi’s time there came out of Mali. In the summer of 2012 Islamist radicals linked to Al Qaeda hijacked a secessionist movement in the northern part of the country, capturing cities and imposing sharia law. The Islamists replicated the functions of a state, with courts, police and even press releases. Callimachi developed a rapport with Omar Ould Hamaha, a spokesman for the Islamists whom she plied with questions over the phone.

It was during the holy month of Ramadan, in 2012, that Callimachi thinks Ould Hamaha decided she was an acceptable interlocutor. She called him one day and he was curt, explaining that he hadn’t yet broken his fast. She sent a text message apologizing for the mistimed call. At the same time, Erin Burnett of CNN got hold of him and recorded an interview that went so poorly he hung up on her. The contrast between the pushy television personality and the culturally sensitive reporter was clear, and Callimachi became Ould Hamaha’s favorite journalist.

Although he occasionally exaggerated the Islamists’ successes, Ould Hamaha proved to be a reliable source. He told Callimachi that the Islamist militias were in possession of the SA-7 surface-to-air missile, a claim she didn’t feel comfortable reporting at the time, given the lack of hard evidence. Months later she found that the fleeing Islamists had left behind a manual for that very weapon. “To me, it was the ‘aha’ moment,” Callimachi says. Terrorists didn’t merely spout propaganda; they could also provide information. 

In January 2013, unable to retake the territory, the Malian government invited France to intervene. After French forces liberated Timbuktu, the fabled cultural capital of medieval Africa, journalists scrambled to get there. The French were flying in only the big-name television networks, and the few roads linking Timbuktu to Mali’s capital, Bamako, were dammed with checkpoints. No one knew exactly where the Islamist militias were.

Callimachi was determined to get to the city. “Timbuktu is the only romantic dateline in this country,” she told a fellow journalist trying to talk her out of the trip. So she found one route that traversed a dry lakebed, which turned out to be not so dry. After aborting that attempt and several others, she found another route: an ancient road to the city. Callimachi and several other journalists took two cars and set off into the desert. When another reporter asked Callimachi’s AP colleague Baba Ahmed what the chances of success were, Ahmed replied, “cinquante-cinquante”—50-50. Indeed, the journalists were chased by a suspicious SUV and they passed through a town that was still crawling with Islamists. Late at night they arrived in Timbuktu and encountered their first military checkpoint. The Malian soldiers inspected the journalists’ passports and said one word: “Bravo.”

Whereas most journalists filed a few stories and left in days—the city was running low on fuel and beer—Callimachi stayed weeks. Her competitors crowned her “the queen of Timbuktu.” One piece she wrote in that time, which the AP submitted as part of her Pulitzer application, reads like a short story. In it she recounts the tale of a woman whose romance ran afoul of the Islamic police, which punished her with a public flogging. It ends with the woman celebrating in a now-free Timbuktu:

In recent days, she pulled out her lover’s gift of the violet bazin with the flame-patterned brocade from the bottom of a pile of clothes she was not allowed to wear under the city’s occupiers. She painted her lips a translucent fuchsia. She went to the newly opened hairdresser.

The photo studio where she and her lover posed by the cardboard waterfall remains closed, so instead her brother snapped a picture of her.

If you look closely, you can see the marks left by the whip across her now-naked shoulders.

In Mali, as in New Orleans, Callimachi found a way to write about corpses. (There was also the time, years earlier, when she gained access to documents from a morgue in the Ivory Coast that offered evidence of politically motivated assassinations.) After Timbuktu had been retaken, Malian soldiers had killed ethnic Arabs in reprisal, accusing them of collaborating with the Islamists. Callimachi got a tip that some victims were buried north of the city. She and Ahmed bought a shovel, found the sandy gravesite and started digging. They uncovered two bodies, contacted the families and filed their first story. Soon, for ethnic Arabs searching for family members, she and Ahmed became the go-to exhumers.

Callimachi’s biggest discovery in Timbuktu involved remains of a different sort. In their haste to escape from the city, the Islamists left behind thousands of pages of documents. Armed with surgical gloves and trash bags, Callimachi went building to building, collecting anything written in Arabic, the language of the Islamist occupiers. She returned to Dakar with seven full bags. 

“It blew open this beat for me,” Callimachi says of the trove. “There’s so much misinformation about Al Qaeda because it’s a secretive organization.” The documents revealed a terrorist group that was less a fly-by-night operation than a sophisticated enterprise with all the trappings of a modern corporation. In one letter the leaders of Al Qaeda’s North African franchise upbraided a subordinate who failed to answer his phone and collaborated poorly with his fellow terrorists. Members of the organization were required to submit expense reports, and more than 100 receipts cataloged the mundane purchases—“the equivalent of $1.80 for a bar of soap; $8 for a packet of macaroni; $14 for a tube of super glue,” she wrote. In 2014 the Pulitzer board gave Callimachi her second nomination, citing “her discovery and fearless exploration of internal documents that shattered myths and deepened understanding of the global terrorist network of Al Qaeda.”

Just as the Islamist takeover of Mali in many ways served as a preview of the Islamist takeover of parts of Iraq and Syria, so Callimachi’s reporting on the former informed her work on the latter. One of the things she learned from the Timbuktu documents was how much Al Qaeda relied on kidnapping ransoms for revenue—$66 million in 2013 alone, she reported in her first major article for the Times.

As she was working on that story she learned about the Westerners taken hostage by what would later become known as the Islamic State. It was an uncomfortable subject to report, in part because hostages’ families viewed the press with suspicion. But it resulted in articles such as “The Horror Before the Beheadings,” in which Callimachi recounted never-before-heard details about the suffering hostages endured “in the Islamic State’s underground network of prisons in Syria.” (In her original draft she used the phrase “underground gulag,” but the copyediting desk nixed it on the grounds that gulags were exclusively Soviet. The poet in her objected. “Losing that word was hard for me.”)

As with any other beat, inside sources enrich her coverage of the Islamic State. These she has developed on Twitter. She finds the profile of a jihadist, requests that he follow her account and—for those who follow her back instead of issuing a tirade of animal-themed insults—starts talking. The conversation usually moves to a secure messaging platform, which is why Callimachi’s iPhone now boasts a teenager’s quantity of messaging apps, including Whats-App, Kik, Telegram, Wickr, and Signal.

Most of the sources she messages are Islamic State fanboys, not actual players, but some are in touch with people in Iraq and Syria and have access to password-protected websites. Through these channels she has obtained privileged information about the Islamic State’s plans, often well before other publications—and even before governments. Her jihadi contacts have acquired a begrudging respect for her, gained through a commitment to accuracy. She sealed her relationship with one when she issued a correction to a story in response to his complaint.

It was through one such source that Callimachi learned that the Charlie Hebdo attack this January, carried out by the brothers Chérif and Saïd Kouachi, was the work of Al Qaeda in the Arabian Peninsula—and not, as many initially believed, the Islamic State. “Rukmini, I’m telling you, it’s us,” she remembers her source saying. Soon after flying to Paris from Senegal, where she had been in the middle of a vacation with her husband, Callimachi filed a story that carried that source’s claim that the joint timing of the Charlie Hebdo shooting and a series of simultaneous attacks perpetrated by Amedy Coulibaly, an Islamic State supporter, did not indicate that the two groups were cooperating. The Times’ decision to grant anonymity to a terrorist turned out to be controversial. James Comey, the director of the FBI, called it “mystifying and disgusting.”

Margaret Sullivan, the Times’ public editor, defended the choice, arguing that readers are best served by information, no matter its origin. But Callimachi admits that this is uncharted territory for reporters, who are trying to work out the propriety of dealing with extremist sources. “When I speak to this source and others I’m conscious of the fact that I’m speaking to a terrorist,” she says. “I’m always a little bit worried: Is it okay that I’m talking to them? But no matter what, this is a very hard beat that I think requires unconventional sources.”

In Paris, as her competitors pumped out daily dispatches, Callimachi and her colleague Jim Yardley got to work on a pointillist portrait of the Kouachi brothers. The city was packed with journalists, many of them natives with contacts deep inside the French government and police. But Callimachi reconnected with a source from a previous story, who told her how to get legal documents from one brother’s terrorism case. The thousands of pages of documents, handed over on a USB stick, gave her the raw material to detail the brothers’ radicalization. “And suddenly,” she says, “I had something.”                                                                   

Stuart A. Reid is an editor at Foreign Affairs.