Preview by Frank Belknap Long is a science fiction short story written in the mid-20th century. It centers on a film preview that turns into an alien intrusion, exploring how perception can be hijacked and how memory and culture can be stripped away by watchers beyond Earth. At a private screening, the smooth-talking Mr. Scanlon promises critics a new, brutally realistic experience and showcases Stella, a “stripped” actress. A grand Western unspools, then ruptures: a tentacled being rides into the Black Hills, the landscape mutates, Stella grotesquely transforms, and Scanlon abruptly vanishes. The tale closes with a chilling coda: a week later saucer-folk arrive in force and erase from human minds the treasured knowledge of Earth’s wonders, ensuring that no one remembers the preview—or understands why it happened.