USA, 1954, b/n, 35 mm, 93′
di Gordon Duglas
Sceneggiatura Ted Sherdeman – Fotografia Sidney Hickox – Montaggio Thomas Reilly – Musiche Bronislau Kaper – Interpreti James Whitmore, Edmund Gwenn, Joan Weldon, James Arness, Chris Drake – Produttore David Weisbart

New Mexico State Police Sergeant Ben Peterson (James Whitmore) and Trooper Ed Blackburn (Chris Drake) discover a little girl in shock wandering the desert near Alamogordo, New Mexico. They retrace her steps to a mobile home owned by an FBI Special Agent named Ellinson on vacation with his family. The trailer side is ripped open from the outside; no trace is found of the rest of the family. Only a single, unidentifiable footprint is left behind. A strange, pulsating high-pitched noise comes on the desert wind, and the little girl briefly reacts to it, but no one around her notices.