Bollywood mystery action flick, Post Box 999, directed by Ravindra Dave and written by P. L. Santoshi was released in the year 1958. The movie starred Sunil Dutt and Shakila in lead roles while Krishnakant, Leela Chitnis, Manorama, Poornima, Ramayan Tiwari, Amarnath, Ramesh Sinha and Sadhana also played important characters in the film. The melodious music of the movie was composed by none other than the hit veteran music director duo Kalyanji Anandji while the songs were rendered by Hemanta Mukherjee and Lata Mangeshkar.

Mohan ( Kundan ) is living alongwith his mother. He is in love with a beautiful young woman named Shyama ( Sadhana ). They both are planning to get married to each other in near future. Unfortunately, Shayam is found dead just few days before of their marraige date. An eyewitness named Bindiya ( Poornima ) identifies Mohan as the killer. Mohan is arrested by police and is presented in the court. He is found guilty and sentenced to prison for a long term. His mother than announces a reward of Rs. 10000 to whoever can prove Mohan innocent.

After five years, a reporter named Vikas ( Sunil Dutt ), who works in Prakash Publication comes forward to accept the challenge. A young women named Nilima ( Shakila ) decides to assist him in his investigation. Vikas and Nilima falls in love with each other. Nilima is then abducted by a guy named Shamsher Singh, who is actually the real killer of Shyama.

The songs of the movie are:

1. Neend na mujhko aaye