By recounting how Lu Xun 鲁迅 went from studying medicine in Japan to writing for the magazine Xin qingnian 新青年 (New Youth), the preface to Nahan 呐喊 (Outcry, 1923), Lu Xun's first collection of short stories, not only presents an origin story of an important author but also contains important clues for understanding modern Chinese literature. This article offers a new reading of that canonical text by focusing on the problem of medium. Synthesizing author biography, media history, and textual analysis, it examines three intermedial references in the preface—the famous lantern slide, the modern periodical, and the recurring notion of outcry. As an autobiographical account, the preface contains narrated events that call for more media‐centered analysis, including the “slide incident” (renamed “screen incident”) and Lu Xun's failed experiment with the periodical medium. Reading the preface as an act of narration, this article scrutinizes textual choices such as the confusing word dianying 电影 (film) and the outcry metaphor. The emergence of both modern vernacular literature and Lu Xun as a major literary figure, it is argued, should be historicized in a broader transnational media environment, in which diverse media practices intersected.