The bullet that pierced Abraham Lincoln’s skull on the evening of April 14, 1865 put an end to the life of a man whom many believe to be the greatest American president. Lincoln was certainly the best-known victim of the projectile that assassin John Wilkes Booth fired from his Derringer pistol at Ford’s Theatre on that spring night so many years ago. However, nearly two decades after Lincoln’s death, Booth’s bullet would claim another life, this one the victim of the effects the ill-fated piece of metal had on the psyche of a troubled and guilt-stricken man.

Accompanying Lincoln and his wife, Mary, to the theater that night were Henry Rathbone and his fiancée, Clara Harris, both young and respected members of Washington, D.C. society. Harris was a well-known socialite and the daughter of a U.S. Senator. Rathbone was an army major and the son of a former mayor of Albany, New York. He was also a wealthy man, having inherited a large estate upon his father’s death. Though Rathbone and Harris had grown up as stepsiblings (with Rathbone’s widowed mother marrying Harris’s widowed father), they shared a bond beyond friendship and ultimately became engaged, committed to spending the rest of their lives together as husband and wife.

On their way to Ford’s Theatre, as the Lincolns and their guests travelled by carriage through the fog-shrouded streets of D.C., they may have discussed the surrender five days earlier of Confederate General Robert E. Lee’s troops to Union General Ulysses S. Grant. This laying down of arms had essentially ended the Civil War, which for four years had torn apart the nation and dotted its landscape with the bodies of more than 600,000 men. Though Lincoln had proven victorious in his efforts to reunite the North and South, years of strain now showed upon his face as he confronted both the ire of the defeated Confederacy and—perhaps more troubling—recent dreams of his own impending death.

Once at the theater, the Lincolns and their guests ascended to the Presidential Box and joined 1,700 other patrons in watching a comedy called “Our American Cousin.” The mood was lively, with the crowd giving Lincoln a standing ovation and the orchestra playing “Hail to the Chief” as he entered the theater. Yet creating a cloud of darkness in the otherwise pleasant atmosphere was a man whose thoughts were far more sinister. This man, a Confederate sympathizer, was at the playhouse not for mirth, but for murder. His plan? To assassinate the president.

Two years earlier, actor John Wilkes Booth, had trod the Ford’s Theatre stage in a play called “The Marble Heart,” a performance that Lincoln had attended. Booth had also appeared in several of Shakespeare’s plays, including as the titular male character in “Romeo and Juliet” and as Marc Antony in “Julius Caesar.” Yet hidden beneath the façade of a distinguished thespian was an embittered man seething with hatred for the president. Booth, an ardent anti-abolitionist, saw Lincoln as a tyrant and hoped to cripple the federal government as it began the precarious work of reuniting the nation. To Booth, the president’s death would accomplish just that.

Through his familiarity with the evening’s play, Booth knew of a scene when the audience would break into laughter loud enough to mask the sound of a gunshot. At that moment, Booth, having entered the Presidential Box, pointed his gun at Lincoln. He took aim, steadied his hand, and shot the president behind the left ear at point-blank range.

For a few moments, confusion paralyzed Lincoln’s companions. Then, as the first lady screamed and the president slumped in his chair, Henry Rathbone leapt to action. He rushed toward Booth in an attempt to prevent the assassin from escaping. Booth slashed at Rathbone with a dagger, then plunged the weapon into the latter man’s arm. Despite his injury, Rathbone again tried to detain Booth. He managed to grab the assailant’s coat before Booth jumped from the box and onto the stage, from there crossing the floorboards and making his escape. (Twelve days later, federal soldiers tracked Booth to a Virginia farm, where he was shot in a barn the troops had set on fire; Booth would die a few hours later.)

Back at Ford’s Theatre, the scene of chaos that reigned in the Presidential Box soon spread throughout the building. Lincoln was still alive, but upon examining him, doctors determined he was mortally wounded. The president was rushed through the rain to a boarding house across the street. It was there where he died the following morning, having never regained consciousness. “Now he belongs to the ages,” Secretary of War Edwin Stanton is reported to have said upon the president’s passing.

As the government officials, family members, and physicians in attendance at Lincoln’s death grappled with their feelings of bewilderment and despair, lost was the fact that Rathbone had received a wound so severe it threatened his own life. Booth’s knife had plunged into Rathbone’s arm almost to the bone, severing an artery in the process. Rathbone lost a significant amount of blood and faded in and out of consciousness. He eventually received care for his injury and recovered. Yet as Rathbone’s body healed and the country, both North and South, settled into a period of extended mourning, the young major’s presence at the assassination—as well as his belief, however misguided, that he could have done more to help the president—started a mental deterioration that, years later, would affect Rathbone and his family in an appalling way.

After the tumult surrounding Lincoln’s death had subsided, Henry Rathbone married Clara Harris in July 1867. The couple settled into a spacious home in Washington, D.C. where they raised their three children—two sons and a daughter. Yet though the Rathbones enjoyed the privileges of wealth and an elevated position in society, all was not well. Henry’s feelings of guilt over the assassination—feelings aggravated every year when, on the anniversary of Lincoln’s death, journalists sought him out for interviews—led him to drink and gamble heavily. Though he had always tended toward depression, Henry became increasingly paranoid, believing that Clara was having an affair, or that she was planning a divorce and would take the children away from him. His mental instability was such that it prevented Henry from holding a steady job, a fact that likely aggravated his feelings of distrust and inadequacy.

To a degree, Clara was sympathetic to her husband’s plight. She had noted to a friend: “I understand his distress…in every hotel we’re in, as soon as people get wind of our presence, we feel ourselves becom[ing] objects of morbid scrutiny.” She added: “Henry…imagines that the whispering is more…malicious than it can possibly be.” Modern-day medical professionals have speculated that Henry Rathbone suffered from schizophrenia or perhaps a severe form of post-traumatic stress disorder induced by his presence at Lincoln’s assassination. However, the state of mental health treatment at his time was such that Henry received no substantive help for the psychological issues that plagued his mind and that seemed to grow worse every year.

In 1882, the Rathbones moved to Germany, as Henry had been appointed U.S. consul to the city of Hanover. Perhaps Clara regarded this as an opportunity for a fresh start, a chance to escape the stares and discreetly pointed fingers that seemed to drive Henry’s paranoia. Yet it was there, on December 23, 1883, that Henry’s madness came to a head. Though accounts differ as to what exactly happened, early that morning, two days before Christmas, Henry either tried to enter his children’s bedroom or actually attacked them. To protect their offspring, Clara distracted Henry; whatever events ensued between husband and wife ended with Henry shooting Clara several times, stabbing her, and then, in an effort to kill himself, plunging the same knife five times into his own chest.

Henry Rathbone survived his suicide attempt; Clara Rathbone succumbed to her injuries. The news that the heroic figure from Lincoln’s assassination had, in a fit of madness, become a murderer himself made banner headlines across the Atlantic. It was quickly determined that Henry wasn’t competent to stand trial, so he was placed in an asylum in Hildesheim, where he spent the remaining 27 years of his life. Henry died in August 1911 at the age of 74 and was buried in a city cemetery in Hanover alongside Clara. In 1952, some of the cemetery’s graves—including the Rathbones’—were cleared for reuse; thus, the disposition of the remains of Henry and Clara Rathbone is unknown.

Such was the degrading end for a couple who, in their younger years, had anticipated a long and loving future together. Clara had been a bright, respected woman, a shining star of Washington, D.C. society. Henry would leave behind a more ambiguous legacy: one of bravery for his heroic attempt to detain the president’s murderer, and heartbreak for the fact that Lincoln’s assassination and Henry’s own mental illness would cause the hero to become a murderer himself.