Draft is a series about the art and craft of writing.

When I was a child, my family spent several summers in Amsterdam. My mother, sister and I toured the city, wandered along the canals, visited the great museums and sampled the local chocolates. My father, meanwhile, buried himself in Amsterdam’s social history library, studying the papers of the anarchists Emma Goldman and Alexander Berkman, known as Sasha. Sasha and Emma had been born in czarist Russia, immigrated to New York in the 1880s as teenagers, joined an anarchist group, and formed a lifelong friendship that remained immutable through protest rallies, bombing plots, prison time, love affairs, deportation, separation and war. My father, Paul Avrich, had been fascinated with them for years.

My father, who died in in 2006, was a professor of Russian history, a scholar drawn particularly to the radical underpinnings of that vast, doleful country. While he was researching the threads of political and social unrest, he was led to investigate anarchism and its adherents, men and women from around the world who espoused a Utopian society without government and fought tirelessly for their improbable goal.

When my father began to interview anarchists who had been active at the height of the movement in the early 20th century, he was smitten by their vivacity and stubborn idealism, intrigued by the stark contradictions of fanaticism and cerebral enlightenment. He traveled to meet them, listened to their stories, perused their precious letters and photographs, disarmed them with his palpable enthusiasm and curiosity. He chronicled their political influence, heroism, crimes and misdeeds, and became known as the leading scholar of the anarchist movement. He wrote about Russian uprisings, ruthless bomb makers, the doomed Sacco and Vanzetti, the tragic Haymarket incident.

Yet his longstanding hope was to undertake the epic story of Goldman and Berkman. The iconic, brazen Emma was far better known, although Sasha had achieved a measure of notoriety when he tried to assassinate the industrialist Henry Clay Frick in 1892, deeming his attack “the first terrorist act in America.” A dual biography of Sasha and Emma, my father believed, would be the crowning accomplishment of his career.

Although my father was modest about his intellectual gifts, his brilliance was stunningly apparent. He went to college at 16, became fluent in a half-dozen languages and conversant in a half-dozen more, cracked intricate Soviet codes as an Air Force officer stationed in Germany, was an inspiring lecturer and teacher, and published a series of acclaimed books. He knew a great deal about literature, opera, theater. He also was an intensely disciplined man, working seven days a week, usually in his small study at the back of the family apartment on Riverside Drive. It was a somewhat spartan space, holding a plain desk, piles of books and files, and stacks of yellow pages covered in his slanting, looping longhand. There was no television or radio playing, no art on the walls; the window looked out onto a glum section of courtyard. The only occasional distraction, a cat sprawled across the desk, tail swishing deliberately through sheaves of paper. Otherwise, just my father alone, deep in concentration.

In the 1990s, my father became gravely ill. He struggled valiantly to regain his health and faculties, but resuming work was difficult. He tired easily, and the vivid, fluid lectures that had poured from him, mesmerizing and note-free, were now scripted and recited. His languages deserted him. Most painful for him, the realization that his book about Sasha and Emma, despite years of planning, would go unfinished.

It was then that he asked me to take over the project. Rather blithely, I agreed. I was a writer with a knack for research and a background in history; the subject was compelling; it would be a good opportunity to learn more about my father’s oeuvre. (I was abashed at reaching adulthood without having read all of his published books). Above all, I wanted to help. We had little time, however, for a conventional collaboration. While I was still in the early stages of preparing the manuscript, mechanically organizing his drafts and notes, sorting transcribed letters, familiarizing myself with the basic chronological framework, my father weakened further. Our last visits were spent discussing “Sasha and Emma.” We sat together, looking at the photographs that would go into the book. He chose his favorites one by one, pleased to be able to make this final contribution.

The first months following my father’s death were unsettled. Friends and family expressed open relief that he was freed from his ordeal, and initially I felt the same way, although soon I began to miss him. I noticed new movies he would have liked, restaurants he would have enjoyed. For all his academic asceticism he loved a fine meal, and when we dined out together, he would tell me tales about his work — a federal detective’s coast-to-coast hunt for a slippery bomber, the sad fate of the Haymarket anarchists — stories I now recalled as I turned back to “Sasha and Emma.” My father’s notes were on my desk, his voice in my head, and I was mindful of his specific writerly style and slightly old-fashioned cultural sensibility. As I researched the book, I grew increasingly conscious of my responsibility to honor his professional reputation. I apprehended just how much I had to learn, and the blunt enormity of the task. I was overwhelmed by a chilly, breathtaking pressure.

It was Sasha and Emma who guided me through this literary panic. Methodically, but with mounting regard, I read their blistering tracts and poignant letters. The more I got to know them, the fonder I became (their indefensible violent acts notwithstanding). They were plucky and droll, both evocative writers. Soon their voices echoed in my head, alongside my father’s. Emma could be caustically imperious, yet also generous and loyal, a passionate defender of civil rights. I was, perhaps, less forgiving than my father of Sasha’s blindly aggressive nature, but I admired Berkman’s wit, dignity and resolve. I marveled at the bold exploits and reckless daring of their anarchist comrades. When I unearthed accounts of their activities in century-old newspapers, I felt like a time traveler. The book, I knew, would take me years to complete, yet I was determined to see it through properly. I believed I owed it not just to my father’s legacy, but to the fearless, maddening radicals who sacrificed so much for their ideals.

Shortly after my father’s death, when it became known in his circle that I had taken over “Sasha and Emma,” one close anarchist friend, already approaching 90, informed my mother that he intended to stay alive until the book was published. This formidable declaration rooted itself in my brain as I grappled with the manuscript. Every six months or so, with escalating suspense, I’d ask my mother to call him in Toronto and check on the state of his health. He was hanging in there. In October 2012, I received a few early copies of “Sasha and Emma.” The book looked beautiful to me: Goldman and Berkman’s sober faces staring up from the elegant jacket, my father’s name printed below. I experienced keen regret that my father and I would not be able to have one last dinner, talking about Emma and Sasha and their friends, all the details I had discovered, all the stories he had yet to tell. But I also felt a certain contentment. I went straight to the post office to overnight a copy to the gentleman’s home in Canada, suppressing concern that he would turn to the first page and instantly keel over.

The next day, still sharp and hale, he telephoned my mother. The book was in his hands; emotion was in his voice. “Paul Avrich lives,” he said.

Karen Avrich is the co-author of “Sasha and Emma: the Anarchist Odyssey of Alexander Berkman and Emma Goldman.” She lives in New York City.