Turner (Halle Berry) is an operator at a 911 reporting center. One day, she received a call from a little girl, claiming that a stranger broke into her home. Turner immediately asked her to hide. However, the call was suddenly disconnected at this time. Turner anxiously called back, but unexpectedly, the girl's hiding place was exposed, causing her to be killed by the intruder. From then on, Turner fell into the abyss of guilt and could no longer work as an operator. Six months later, Turner became an operator mentor. On this day, a novice received a call reporting a crime. The girl Casey (Abigail Breslin) on the other end was trapped in the trunk of a car by the kidnappers. The situation was very critical. After investigation, Turner actually found that the gangster was the murderer who killed the little girl that year. Out of indignation and atonement, she immediately made up her mind to personally arrest the gangster. A thrilling telephone hunt is about to begin, but what everyone did not expect is that a secret hidden for many years gradually surfaced...