The kidnap of a child goes wrong and the child dies. An old lady is the only witness having heard the disguised voice of the kidnapper from outside a public telephone box. To trap the murderer she tells the press she has seen his face.

A kidnap plot goes wrong resulting in the death of a child. The police have only one lead, an old lady who has a vague recollection of the kidnapper leaving a public telephone box. To catch the murderer she acts as bait by telling the press that she has seen the killer's face.