Cary now undertook his great works examining historical and social change in England during his own lifetime. The First Trilogy (1941–44) finally provided Cary with a reasonable income, and The Horse's Mouth (1944) remains his most popular novel. Cary's pamphlet "The Case for African Freedom" (1941), published by Orwell's Searchlight Books series, had attracted some interest, and the film director Thorold Dickinson asked for Cary's help in developing a wartime movie set partly in Africa. In 1943, while writing The Horse's Mouth, Cary travelled to Africa with a film crew to work on Men of Two Worlds. Cary travelled to India in 1946 on a second film project with Dickinson, but the struggle against the British for national independence made movie-making impossible, and the project was abandoned. The Moonlight (1946), a novel about the difficulties of women, ended a long period of intense creativity for Cary. Gertrude was suffering from cancer and his output slowed for a while. Gertrude died as A Fearful Joy (1949) was being published. Cary was now at the height of his fame and fortune. He began preparing a series of prefatory notes for the re-publication of all his works in a standard edition published by Michael Joseph. He visited the United States, collaborated on a stage adaptation of Mister Johnson, and was offered a CBE, which he refused. Meanwhile he continued work on the three novels that make up the Second Trilogy (1952–55). In 1952, Cary had some muscle problems which were originally diagnosed as bursitis, but as more symptoms were noted over the next two years, the diagnosis was changed to that of motor neuron disease, a wasting and gradual paralysis that was terminal. As his physical powers failed, Cary had to have a pen tied to his hand and his arm supported by a rope in order to write. Finally, he resorted to dictation until unable to speak, and then ceased writing for the first time since 1912. His last work, The Captive and the Free (1959), first volume of a projected trilogy on religion, was unfinished at his death on March 29, 1957.