In the mid-1970s, he reluctantly put aside his acting career to run an art gallery. In the 1980s he wrote "In Search of My Father: A Portrait of Leslie Howard", a biography covering the career and mysterious death of his father, whose plane was shot down over the Bay of Biscay on 1 June 1943. His conclusion (which remains in dispute) was that the Germans' goal in shooting down the plane was to kill his father, who had been travelling through Spain and Portugal, ostensibly lecturing on film, but also meeting with local propagandists and shoring up support for the Allied cause. The Germans suspected surreptitious activities since German agents were active throughout Spain and Portugal, which, like Switzerland, was a crossroads for persons from both sides of the conflict, but even more accessible to Allied citizens. The book explores in detail written German orders to the Ju 88 "Staffel" based in France, assigned to intercept the aircraft, as well as communiqués on the British side that verify intelligence reports of the time indicating a deliberate attack on Howard. Ronald Howard was convinced that the order to shoot down the airliner came directly from Joseph Goebbels, the Nazi Minister of Propaganda, who had been ridiculed in one of Leslie Howard's films, and who believed him to be the most dangerous British propagandist.