Christine Gregg delivers a noteworthy performance within this brief drama. Her portrayal of "Jean" depicts a young woman who works occasionally at the neighborhood pub before taking the final bus home from a phone booth. One evening, the phone rings; she answers, and finds herself drawn in by the pleasant voice on the other end of the line. She quickly develops an obsession with these calls, and as is revealed, coinciding with reports of young girls being targeted by an unknown assailant, concerns arise that she might be selected as his next victim. Thankfully, she shares her developing feelings with her younger sister, "Ann" (Janina Faye), who offers warnings about potential risks and demonstrates a surprising level of understanding when the situation demands it. Viewing this production nearly six decades after its creation, a sense of unease remains palpable, and Pat Jackson successfully conveys a considerable amount within the hour’s runtime. It's tempting to criticize the recklessness and inexperience displayed by the young woman—and her family—but the story continues to hold relevance given how common phones have become, how private they once were, and how vulnerable children remain to persuasive voices and romantic fantasies.

Source on TMDB