On February 19, 1942, Otto Kuehn undergoes a secret military trial for espionage in a Honolulu courtroom. Captain Eugene Slattery leads the prosecution for the tribunal, with Major General James Woodruff presiding over a five-officer jury. Major Harrison M. Coppin, Otto’s military defense attorney, has had little time to prepare. After the three charges are read, Otto impulsively speaks, then pleads not guilty.

Slattery gives an opening statement detailing the prosecution’s case, but Coppin declines to give one in defense of Otto. The first witness, Kimie Doue, testifies that Otto visited the Japanese consulate multiple times in 1941, much earlier than he claimed in his confession, and that Consul General Nagao Kita and Vice Consul Otojiro Okuda seemed to know him. Coppin’s desultory cross-examination focuses on irrelevant details, such as the consulate’s floor coverings. FBI Special Agent J. Sterling Adams then testifies about Otto’s un-American activities.

The next morning, Robert Shivers details the FBI’s three-year investigation. Again, Coppin declines to cross-examine. Eberhard Kuehn is called to testify about a Japanese man visiting their home in October 1941; he tentatively identifies a photo of Takeo Yoshikawa. As Eberhard leaves the stand, he passes his nine-year-old brother Hans, and they share a long hug while their father watches. When a frightened Hans takes the stand, he says that he and his father drove near Pearl Harbor and saw ships one day. On cross-examination, he admits to not knowing where Pearl Harbor is and states that nobody coached him on what to say in court. Court adjourns, and the narrator imagines Otto contemplating the bitter situation of his sons being forced to testify against him in a case that could cost him his life.

On the trial’s final day, a Navy officer testifies that Pearl Harbor was attacked. A consulate witness states that Otto had special access to the Consul General’s office for years. The prosecution rests. Coppin calls two family friends to attest to Otto’s character, then a bank cashier who provided information to the FBI but never interacted with Otto personally. The defense rests after calling only three witnesses.

Otto testifies. He admits to giving the Japanese the signal system but claims that he never intended to use it; he also states that his ship reports to the Japanese were fictional. He acknowledges lying about owning a shortwave radio and driving near Pearl Harbor with Hans, but he claims that they were only looking at houses to buy. He concedes delivering the signal plan and pleads that he should have reported the contact, but he does not consider himself to be a criminal. Coppin makes no closing argument in Otto’s defense.

The commission deliberates for a mere 11 minutes, and Major General Woodruff then announces the verdict: Otto is found guilty on all three charges and is sentenced to death by firing squad. Otto shows no reaction and is returned to his cell. All present are sworn to secrecy. 

In 2022, the narrator gives her husband Mark the trial transcript. She reflects on the pain that her father and uncle must have endured while testifying against Otto. Mark questions the trial’s fairness, noting that the judge, jury, and defense attorney were all military officers who must have held great anger toward Otto in the wake of the attack on Pearl Harbor. The narrator’s father believed that Otto became a convenient scapegoat. While acknowledging possible unfairness in the trial, the narrator also remains convinced of Otto’s guilt and believes that the sentence was warranted.

The narrative shifts to a different case whose outcome has a bearing on how Otto will be treated. In May 1942, two German submarines carrying saboteurs depart France for the United States to destroy American infrastructure. The first lands on Long Island on June 13. Group leader George Dasch encounters Coast Guard seaman Jack Cullen on a foggy beach. When one saboteur speaks German, revealing the men’s true nationality, Dasch bribes Cullen with $300 instead of killing him. Cullen flees to alert authorities, but the German saboteurs escape; their explosives and uniforms are later found buried in the dunes. Four days later, the second group lands at Ponte Vedra Beach, Florida without incident.

Convinced the mission is doomed, Dasch travels to Washington and surrenders to the FBI, enabling the capture of the remaining seven saboteurs. President Roosevelt orders a secret military tribunal. On July 31, the Supreme Court rules that the tribunal does indeed have jurisdiction over this case because the United States is at war. All eight men are sentenced to death, though Roosevelt commutes two sentences, including Dasch’s. The remaining six are executed. This case later shapes Otto Kuehn’s fate.

In 2002, the narrator coincidentally lives in Ponte Vedra Beach near the saboteurs’ landing site. She describes visiting her father in an assisted living facility. His memory is deteriorating due to his dementia. When asked about Pearl Harbor and his father, Eberhard offers only vague responses or incorrectly says that his father died of cancer in Germany. The narrator realizes that for her father, those traumatic memories are gone now; she understands that he chose to bury the past rather than let it haunt him.

News of Otto’s death sentence reaches President Roosevelt on March 4, 1942. The Justice Department immediately questions its validity; because Otto’s spying occurred before war was declared and before martial law commenced in Hawaii, a military commission may have lacked jurisdiction. By law, a civilian retrial could not impose the death penalty, and many who desire to punish Otto severely find this unacceptable. J. Edgar Hoover and the FBI press Attorney General Francis Biddle for a quick execution. Special Agent Shivers argues that a military-commission death sentence would boost public morale.

On April 6, Lieutenant General Delos Emmons, Hawaii’s military governor, orders Otto to be shot immediately, but Biddle stays the execution. In August, Hoover again presses for arrangements for an early execution. However, the Justice Department is awaiting the Supreme Court’s full written opinion on the German saboteur case, which will establish precedent. Issued October 29, the opinion upholds the saboteurs’ executions because they were sentenced by a military tribunal during wartime. Because Otto’s spying occurred during peacetime, his tribunal lacked the authority to impose the death penalty. To avoid any legal challenges, Emmons commutes Otto’s sentence to 50 years of hard labor. Biddle rules the matter closed.

On November 20, 1942, Otto is transferred to Fort Leavenworth, Kansas, to begin serving his sentence. Meanwhile, Japanese consular officials Kita, Okuda, and Yoshikawa are held for questioning. All deny knowing Otto or engaging in espionage, though Okuda admits to traveling with Yoshikawa to Kailua and giving Yoshikawa a package. (This is the package that Yoshikawa then delivered to Otto.) By June, the Japanese officials are freed in a prisoner exchange, frustrating the FBI.

Eberhard turns 16 while he is still imprisoned in the Sand Island internment camp. After five months, Special Agent Shivers, convinced of the boy’s innocence, secures his release in April 1942, though Eberhard remains on probation as an “enemy alien.” He returns to find the family home in disarray and the chickens dead. At first he lives with family friends, then with Pastor Galen Weaver, who becomes a mentor. Eberhard rarely visits his mother because she wants him to live with her permanently in the camp, and the friction between them intensifies.

In September 1942, Hans visits Friedel, who is shocked by his deteriorating condition from pemphigus vulgaris, a painful skin disease. Hans confides that he has been sexually abused and nearly killed by his foster family’s teenage son. Police investigate but file no charges. Hans is moved to a different foster situation and is eventually allowed to live with Friedel at the camp. In early 1943, Sand Island closes. Friedel and Hans are sent to Crystal City, Texas, while Ruth is transferred to Honouliuli Gulch in Hawaii before eventually joining them.

Friedel repeatedly writes Eberhard letters, begging him to rejoin the family, but he refuses. On Christmas Eve 1943, Ruth sends him a desperate plea, echoing her mother. The narrator interjects to state that her sister has discovered a box containing Eberhard’s reply to Ruth; in this letter, he declares that he will never be German again and explicitly condemns the Nazis. Devastated, Friedel secretly contacts her son Leopold in Germany, asking that he petition the Nazi regime to “rescue” Eberhard from the United States. Leopold brings the request to the Foreign Office, where an official threatens countermeasures if Eberhard is not returned. However, nothing ultimately comes of these machinations.

In 1943, Ruth’s husband files for divorce, and the proceedings inevitably reveal the Kuehn espionage story to the public for the first time. Though the divorce is initially denied, the revelation forces the government to issue a press release. On June 15, 1943, newspapers across America run headlines about the Nazi spies who aided the Pearl Harbor attack. 

In January 1944, Friedel writes Otto to explain that because the two can never be together while he is in prison, she will repatriate to Germany with Hans and Ruth, leaving him alone. Otto agrees. When Friedel learns that Eberhard plans to enlist in the US Army, she is horrified to realize that he is committed to fighting against the Reich. In 1944, Eberhard graduates high school, becomes a US citizen, and immediately joins the Army to fight America’s enemies in World War II.

In December 1944, Friedel, Hans, and Ruth are approved for repatriation in a prisoner exchange. On January 7, 1945, they board the MS Gripsholm in Jersey City. After a dispute over prisoner numbers is resolved in Marseille, they arrive at the exchange point in Kreuzlingen, Switzerland, on January 24 and cross into Germany. Finding Berlin under relentless Allied bombardment, they travel to Bregenz, Austria, for safety.

Leopold had earlier sent his wife Ursel and their two sons to Spremberg while he remained trapped in Berlin under Goebbels’s orders. On February 18, he writes Ursel, urging her to go live with his mother’s family in safer ground. The final Allied assault on Berlin begins on April 16. As over a million Soviet soldiers march toward the capital, Leopold is among the last defenders, having been ordered by Joseph Goebbels to fight to the death. On April 30, Adolf Hitler dies by suicide. The next day, Goebbels murders his six children before he and his wife kill themselves. Berlin surrenders on May 2.

Meanwhile, Eberhard completes basic training at Fort Bliss, Texas. In March, his unit is ordered to the front. While Europe’s war ends, Eberhard fights in the Battle of Okinawa, which began April 1. For 82 days, he endures harsh combat, and 12,000 Americans are killed. Friedel, Ruth, and Hans eventually reunite with Ursel and her children in southern Germany. They learn that Leopold was injured in an explosion and died the day after Berlin’s surrender. A postwar photograph captures the devastated family. A letter that Eberhard writes to a friend from Okinawa after the fighting reveals his lifelong pattern of compartmentalizing trauma, for he mentions only ordinary details and blocks out the horrors of war.

In 1948, Eberhard, now a college student, receives a call from his father, who explains that he has been released from prison. After the war, he petitioned to reopen his case, claiming that his trial was a sham. The 1946 Supreme Court ruling in Duncan v. Kahanamoku found that military tribunals in Hawaii had overstepped their authority, paving the way for Otto’s appeal. A hearing board recommended deportation to Germany, and  Attorney General Tom Clark ordered Otto deported as a dangerous alien enemy.

Otto was sent to Ellis Island but was then inexplicably held there for two years, despite orders that he be deported within 30 days. On July 29, 1948, Clark ordered his release on parole. An FBI memo noted that Otto’s destination was unknown and included a handwritten note reading “This is astounding” (213). The memo was marked to be destroyed. Otto settled in Yorkville, New York City, working odd jobs to save money for his passage to Germany.

Upon contacting Eberhard, he asks his son to meet one last time. Agonizing over the decision, Eberhard finally agrees and travels to a coffee shop in New York City in August. He finds his father frail and withered. When Otto begs Eberhard to return to Germany to help rebuild the family, Eberhard angrily refuses, saying that Otto had made him appreciate America and now wanted him to leave. He confronts the suffering that his parents caused Hans, lamenting his own internment and being labeled an “enemy alien.” He no longer considers himself German or even a Kuehn.

Before leaving, Eberhard asks if Otto did everything he was accused of. Otto looks down and says nothing. Eberhard gives him a brief hug, walks out, and never sees his father again.

In 2020, the narrator receives a letter from Lisa, an 86-year-old German cousin who was previously unknown to her. Lisa’s son, Bruno, emails the narrator, and they begin corresponding. New relatives emerge, including Hans’s wife, Olga, and their three sons. In December 2023, the narrator and her sister travel to Germany to meet the family. They meet Leopold’s grandson, Knut, and his family in Frankfurt, then Olga and her sons in Stuttgart. In Berlin, they meet Lisa and Bruno and visit the apartment where their father grew up and where Leopold lived.

The narrative recounts Hans’s life of severe hardship. Falsely branded a child spy in several publications, he suffered physical and emotional trauma from internment, as well as severe physical and sexual abuse in foster care, and his painful skin disease also caused problems. He attempted suicide multiple times before dying by suicide in 1974.

After the war, Friedel advised Otto not to return to the turmoil and poverty in Germany. On December 3, 1948, Otto sailed instead to Buenos Aires, working for years and sending money home while Friedel and Hans struggled with poverty in Tirschenreuth, Germany. In 1945, the government auctioned off the Kuehns’ Hawaii possessions. In 1955, an ill Otto returned to Germany and reunited with Friedel and Hans in a cramped apartment. He died of cancer shortly afterward.

A 1962 newspaper article describes Friedel as a broken woman living on a small pension, though she remains defiant. In the narrator’s present, Olga reveals to her that Friedel desperately searched for Eberhard and lived in constant fear that the FBI would arrest her again. 

The narrative reveals that Friedel died of cancer in February 1964. Ruth flew to Germany for the funeral, and Olga witnessed Ruth clearing out all of Friedel’s documents and photos during the night and burning them in a field. 

The narrative explains that after the war, Ruth returned to the United States in 1949, remarried, and lived quietly, becoming increasingly fearful of FBI surveillance in her later years. She died without ever revealing her past.

In 1989, the narrator and her husband, Mark, visit the USS Arizona Memorial on their honeymoon, as yet unaware of her family’s connection to the tragedy. Upon planning a return trip decades later with her children, she finds herself too anxious to go, imagining tourists recognizing her connection and challenging her presence at the memorial.

She decides to write Family of Spies after witnessing contemporary antisemitic incidents in her suburban Maryland neighborhood, including flyers on lawns and swastikas at the local school. She reflects on how slowly the conflict began in Nazi Germany, then how quickly it unfolded, and she realizes that such violence can happen again and is happening again.

She acknowledges the overwhelming dread of her family’s role in Pearl Harbor but emphasizes that each person chooses their own path, as her father did at age 16. She wishes that he had shared his burden but understands that keeping the secret became his way of life. As dementia erased his traumatic memories, he found happiness in being surrounded by family, and she recalls his contentment at his 80th birthday celebration in 2006. He died four months later.

The narrator concludes, “Secrets eat love like acid. But love regenerates. My father is a testament to that” (227).