This man, who had stood his ground against charging water buffaloes, who had flown missions over Germany, who had refused to accept the prevailing style of writing but, enduring rejection and poverty, had insisted on writing in his own unique way, this man, my deepest friend, was afraid — afraid that the F.B.I. was after him, that his body was disintegrating, that his friends had turned on him, that living was no longer an option.

Decades later, in response to a Freedom of Information petition, the F.B.I. released its Hemingway file. It revealed that beginning in the 1940s J. Edgar Hoover had placed Ernest under surveillance because he was suspicious of Ernest’s activities in Cuba. Over the following years, agents filed reports on him and tapped his phones. The surveillance continued all through his confinement at St. Mary’s Hospital. It is likely that the phone outside his room was tapped after all.

In the years since, I have tried to reconcile Ernest’s fear of the F.B.I., which I regretfully misjudged, with the reality of the F.B.I. file. I now believe he truly sensed the surveillance, and that it substantially contributed to his anguish and his suicide.