“In Jewish lore,” the Israeli attorney Ory Slonim observes, “captivity is regarded as the worst fate of all.” In his new memoir, A Knock at the Door: The Story of My Secret Work with Israeli MIAs and POWs, readers come to understand why and what it means for a society to be guided by this worldview.

Slonim worked tirelessly for more than three decades to secure the release of those Israelis, living and dead, who had been taken hostage by Israel’s enemies.

No other nation in modern history has been so consistently targeted for annihilation. Few other countries have been so consistently subjected to tragedy. In Israel, the late Irish diplomat Conor Cruise O’Brien once observed that “there is always the shadow of a new Holocaust.”

The Jewish state has been under siege since before its reestablishment in 1948. But while Israel has endured more than half a dozen wars and ceaseless terrorist attacks, suffering and bereavement are universal. And they are ever-present in Slonim’s work.

As Slonim writes: “I learned that when it comes to captives and MIAs and the efforts to bring them home — whether alive or in a coffin — there is nothing but an infinite void, a truly bottomless pit. … I realized that no matter what I learned, there were things that I could never understand.”

Slonim adds: “The concepts of ‘success’ and ‘failure’ are highly problematic in this field.” Indeed, as he notes, in more than 30 years of work, Gilad Shalit, who was taken hostage in June 2006 and returned in October 2011, “was the only captive IDF soldier that I ever got to see come back to Israel alive.”

The work is not for the faint of heart. But judging by his memoir, Slonim approached it with deep reservoirs of grace and empathy. He even sets aside chapters for families of the bereaved to offer their thoughts. Israel is the focus of inordinate attention from the press, but the nation’s victims of terrorism are often overlooked in Western media. Slonim deserves credit for recognizing that his story isn’t just about him — he is but an “agent of memory.” Instead, it’s about the families of the murdered and missing. As for the latter, not knowing the fate of their loved ones can be haunting.

Varda Pomeranz, one of Slonim’s colleagues who lost a son in Israel’s war on terrorism, observed that “a missing son is the worst of all. Absence is the worst calamity [because] bereavement is definitive, it is absolute.”

The book’s most meaningful moments come from when Slonim and others, including Pomeranz, plumb the emotional depths of love and loss and when they explore the moral ambiguities and questions that inevitably arise, such as: Is it appropriate, morally or practically, to trade dozens of convicted terrorists for the bones of a deceased Israel Defense Forces soldier?

Slonim recounts the strange journey that led to his pro bono employment as a self-described “door knocker.” His forefathers settled in the land more than a hundred years before the First Aliyah, the period of immigration from 1881-1903 that saw the idea of Zionism, or Jewish self-determination in the Jewish people’s ancestral homeland, beginning to be transformed from a dream to a reality.

From the very start, it was a dream that had to be fought for. As Slonim notes, some of his relatives, members of a Chabad Hasidic sect, were murdered in a 1929 massacre in the town of Hebron. Slonim himself would experience losses from terrorism firsthand.

After service in the IDF and a brief spell as a sailor, Slonim became an attorney, got married, and raised a family. There was little to foretell what was to come. In 1974, he and his wife, Tammy, were attending a theater when a terrorist detonated a bomb, severely injuring his wife and friends and resulting in the termination of Tammy’s pregnancy. Recovering from this loss, Slonim was later called upon to act as an attorney in Israeli military commissions in the 1980s. This work would lead to Israel’s then-president, Chaim Herzog, asking him to “handle the subject of captives and MIAs for a short stint alongside officials from the IDF.” He notes that at this early stage, “there was no title for someone acting in this capacity.”

War has always resulted in missing persons. As Slonim recalls, even as a child he remembers the son of a woman named Chaya who went missing in action in Israel’s 1948 War of Independence.

For subsequent decades, the subject of missing and captured soldiers was exclusively handled by the army. But in the mid-1980s, the rise of terrorism from nonstate actors and events such as the Jibril Agreement of 1985, in which Israel released 1,150 imprisoned terrorists in exchange for three IDF soldiers, led Israel’s leaders to reconsider their approach.

Bureaucracy was an obstacle. “The first two years were very hard because the various bodies making up the elaborate system entrusted with Israel’s defense … didn’t like working with civilians who didn’t rise from the ranks,” Slonim writes. It took two years for Slonim to obtain both the necessary security clearance and title of special adviser to Israel’s minister of defense. Judging by his memoirs, the positions and their duties seemed to be improvised and adapted as time went on.

Slonim successfully pushed for the establishment of a special group in the Mossad, Israel’s foreign intelligence agency, to handle information relating to missing persons. And he encouraged the defense minister to discuss captives and MIAs in “every conversation — whether on political or state security background — with leaders and senior executives of foreign nations” in order to send the message that the issue was a high priority for Israel.

Slonim’s duties had him traveling the world, encountering an assortment of interesting, and sometimes shady, people. Negotiating for the return of the missing requires a no-holds-barred approach and some creative thinking. At one point, for example, he procured special sunscreen to ingratiate himself with the mistress of an East German who he hoped could help him on one of his missions.

A Knock at the Door could benefit from some tighter editing — there are several instances in which the author repeats himself. And there are many others where the reader is left wondering about additional unspoken details. But that might be necessary, as Slonim notes: “Some of my meetings will have to remain confidential, possibly forever.” The book’s frank and conversational tone, however, adds to its raw emotion.

As one family member tells readers: “Our lives here, in the state of Israel, are often characterized by uncertainty, as well as difficult and painful historical events.” A Knock at the Door brings some of those moments home for readers, in all their haunting dread.

Sean Durns is a senior research analyst for the Committee for Accuracy in Middle East Reporting and Analysis.