Alfred Hitchcock did much to popularise the spy film in the 1930s with his influential thrillers "The Man Who Knew Too Much" (1934), "The 39 Steps" (1935), "Sabotage" (1937) and "The Lady Vanishes" (1938). These often involved innocent civilians being caught up in international conspiracies or webs of saboteurs on the home front, as in "Saboteur" (1942). Some, however, dealt with professional spies as in Hitchcock's "Secret Agent" (1936), based on W. Somerset Maugham's "Ashenden" stories, or the Mr. Moto series, based on the books of John P. Marquand.