Editor's Note: On Friday, Feb. 6. 2015, ISIS said the hostage was killed by a Jordanian airstrike.

With ISIS’s brutal murder of Peter Kassig, a 26-year-old American aid worker who dedicated his life to the plight of Syrian refugees, the militant group has one more U.S. citizen remaining in its clutches, according to current and former U.S. officials, as well as individuals involved in efforts to free the Americans.

The hostage is the only American woman held by the militant group. She is the same age as Kassig, and, like him, was kidnapped while trying to help people whose lives have been upended by the long Syrian civil war. She was particularly moved to help children who have been orphaned and separated from their families. The woman was taken in August 2013, along with a group of other aid workers who have reportedly been released.

U.S. officials and the woman’s family have requested that her name not be made public, fearing that further attention will put her in greater jeopardy. No news organization has published her name. But the general circumstances of her capture and captivity have been known and widely reported for more than a year now.

ISIS’s intentions for its remaining American prisoner are unclear. But current and former U.S. officials told The Daily Beast that it was notable she doesn’t appear at the end of a video, released Sunday, that shows the aftermath of Kassig’s beheading. That breaks with ISIS’s pattern of showing the next hostage it intends to kill.

ISIS has killed Muslim women, as well as children. But it has never murdered a female Western hostage on camera. Doing so would mark a radical departure even for a group that has relied on bloody propaganda to lure foreign fighters to its ranks.

A former U.S. counterterrorism official said that before ISIS decides what to do with its remaining American hostage, it will consider carefully the public reaction it could spark. “Before they’re doing anything, they want to have a really good feel for how it will play,” the former official said.

ISIS has reportedly demanded more than $6 million for the remaining American hostage’s freedom, a figure in keeping with the impossibly high ransoms it has placed on other U.S. citizens it has held. The Obama administration has a firm policy of not paying ransom for hostages and has even advised the families of Americans held in Syria that they could be criminally prosecuted if they paid for their loved ones’ releases. (ISIS has freed European citizens, however, from countries where ransoms aren’t illegal.)

The fact that ISIS requests any ransom for its American prisoners and makes it too high for most people to pay indicates that the group isn’t really serious about freeing the Americans, according to current and former U.S. officials and hostage-negotiation experts. Instead, the hostages are being used as props in ISIS’s global propaganda campaign, which is largely aimed at recruiting new followers. Viewed through that lens, ISIS’s American and British captives (the U.K. likewise has an official ban on ransoms) have been more useful to the group for its videos than in raising money, even though ransoms are an important source of ISIS’s income.

The latest ISIS video, showing Kassig’s death, had been expected ever since he was first shown on camera in early October, in another beheading video, and identified as the militant group’s next victim. But this new film differs in key respects from its predecessors, and it may offer new insights into ISIS’s propaganda strategy—and its weaknesses.

The latest video is uncharacteristically long, clocking in at more than 16 minutes, as opposed to the earlier two- to three-minute films showing hostages being murdered. The new video is filled with breathless celebration of the rise of the so-called Islamic State and an exhortation to its followers to join in armed struggle against the “crusader” forces of the United States and the United Kingdom. Indeed, it seems rather desperate in its chest-thumping. It’s also remarkably more brutal—though not to American hostages. A parade of knife-wielding ISIS fighters behead 18 captives, described as Syrian military officers and pilots, in a ghoulish display filled with slow-motion effects and ominous music. It’s by far the most grisly depiction of beheadings ever shown by ISIS.

Kassig is shown only near the end of the video, already beheaded. Unlike other hostages who have read (presumably coerced) statements denouncing the U.S.-led airstrikes, Kassig is never shown speaking. His killer alludes to the fact that he had “little to say” and that other American captives killed before him had already spoken out against the Obama administration. Several current and former U.S. officials speculated that Kassig, who converted to Islam while in captivity and adopted the name Abdul Rahman, might have defied his captors by refusing to read their script or even have insisted on reciting passages from the Quran. “I suspect that Pete knew this was coming and that he refused to talk,” said one individual who has been involved with efforts to free American hostages.

Kassig’s parents had made his conversion to Islam, which they described as genuine and profound, a central pillar of their highly public efforts to free him. The Kassigs, of Indiana, had given television interviews about their son, made YouTube videos pleading with ISIS for his release, and held prayer vigils with members of the American Muslim community. At every turn, they described their son as a faithful follower who had dedicated his life to easing the suffering of innocents.

In a statement Sunday, Kassig’s parents said their son was “fed by a strong desire to use his life to save the lives of others” and that he “was drawn to the camps that are filled with displaced families and to understaffed hospitals inside Syria. We know he found his home amongst the Syrian people, and he hurt when they were hurting.”

President Obama, also in a statement, called Kassig by his chosen Muslim name and contrasted his charity and self-sacrifice with the “darkness” of ISIS. Secretary of State John Kerry called Kassig “a young American who personified the values of altruism and compassion which are the very essence of his adopted religion of Islam.”

ISIS’s long-winded video recites chapter and verse the historic roots of the group, from its early days in Iraq fighting U.S. forces in 2004, and seeks to position the rise of ISIS as an inevitable development in a grand battle against the “crusaders.” The video also argues that ISIS is collecting followers across the Middle East, even as far east as China.

ISIS has a reason to buck up its forces and make itself seem invincible: U.S. airstrikes against the group are starting to yield some results. On Saturday, Iraqi ground forces, supported by American aircraft, took back an important oil refinery in Baiji, about 130 miles north of Baghdad, that ISIS had seized. (Illicit oil revenue has been a major source of the group’s funding.) And the U.S. has been closing in on ISIS’s leader, Abu Bakr al-Baghdadi, though efforts to kill him and his followers have been frustrated by ISIS’s use of encryption to shield its communications from American surveillance efforts.

Still, the video is a reminder of how feckless U.S. efforts to free American hostages have become. Insiders have said the process has been marred by bureaucratic turf wars and a refusal by the United States to negotiate with ISIS, which has freed European hostages in exchange for ransom.

The State Department and the White House have been opposed to paying ransoms, but the FBI and the Justice Department have taken a more nuanced position, according to people involved in the efforts. In particular, the FBI told the parents of James Foley, the first American whom ISIS killed on camera, that they could “walk us right up to that point” of paying a ransom but not be directly involved in exchanging funds, Diane Foley, James’s mother, told The Daily Beast last month.

The FBI has facilitated the payment of a ransom for American hostages before, most notably in 2002, for the release of two Christian missionaries, Martin and Gracia Burnham, who were held by an al Qaeda affiliate in the Philippines. A former U.S. official said the FBI took steps to obscure its role and that the terrorists never knew the U.S. government was involved in the ransom effort.

More recently, a ransom allegedly was paid to free American journalist Peter Theo Curtis in August from al-Nusra Front, al Qaeda’s branch in Syria, according to two sources with direct knowledge of Curtis’s case. Suspicion has focused on the government of Qatar, which has strong ties to Nusra, as the source of the money.

A spokesperson for the State Department has denied that the United States paid a ransom, and administration officials told the Qataris they shouldn’t pay one, either. FBI spokesman Paul Bresson said that the bureau fully complies with U.S. policy as it relates to ransom payments. According to individuals familiar with the matter, Nusra may have hoped that by negotiating for Curtis’s release, it would demonstrate to the United States that it wasn’t as extreme as ISIS and could engage in a reasonable dialogue.

Those hopes might be dashed, however, by U.S. airstrikes in Syria, which have hit Nusra positions, provoking the group’s wrath. Prior to the bombing campaign, which began in September, U.S. intelligence officials warned not to hit the Nusra group, which occasionally has fought alongside U.S.-backed rebels in Syria. Now Nusra is forging an alliance with ISIS, an outcome that had once been considered unthinkable because of a deep schism between ISIS and al Qaeda over the future of the Islamist movement.

How that might effect the Westerners still held in Syria is unknown. The-26 year-old aid worker being held by ISIS isn’t the only one. Freelance journalist Austin Tice was abducted in Syria more than two years ago. The Obama administration has claimed that Tice was held by the Syrian government. But this claim has never been verified and who holds him now is unclear.