Following his first cure, he wrote a detailed appreciation of apomorphine and other cures, which he submitted to The British Journal of Addiction (Vol. 53, 1956) under the title "Letter From A Master Addict To Dangerous Drugs"; this letter is appended to many editions of Naked Lunch. Though he ultimately relapsed, Burroughs ended up working out of London for six years, traveling back to the United States on several occasions, including one time escorting his son to the Lexington Narcotics Farm and Prison after the younger Burroughs had been convicted of prescription fraud in Florida. In the "Afterword" to the compilation of his son's two previously published novels Speed and Kentucky Ham, Burroughs writes that he thought he had a "small habit" and left London quickly without any narcotics because he suspected the U.S. customs would search him very thoroughly on arrival. He claims he went through the most excruciating two months of opiate withdrawal while seeing his son through his trial and sentencing, traveling with Billy to Lexington, Kentucky from Miami to ensure that his son entered the hospital that he had once spent time in as a volunteer admission. Earlier, Burroughs revisited St. Louis, Missouri, taking a large advance from Playboy to write an article about his trip back to St. Louis, one that was eventually published in The Paris Review, after Burroughs refused to alter the style for Playboy’s publishers. In 1968 Burroughs joined Jean Genet, John Sack, and Terry Southern in covering the 1968 Democratic National Convention for Esquire magazine. Southern and Burroughs, who had first become acquainted in London, would remain lifelong friends and collaborators. In 1972, Burroughs and Southern unsuccessfully attempted to adapt Naked Lunch for the screen in conjunction with American game-show producer Chuck Barris. Burroughs supported himself and his addiction by publishing pieces in small literary presses. His avant-garde reputation grew internationally as hippies and college students discovered his earlier works. He developed a close friendship with Antony Balch and lived with a young hustler named John Brady who continuously brought home young women despite Burroughs' protestations. In the midst of this personal turmoil, Burroughs managed to complete two works: a novel written in screenplay format, The Last Words of Dutch Schultz (1969); and the traditional prose-format novel The Wild Boys (1971). It was during his time in London that Burroughs began using his "playback" technique in an attempt to place curses