Miss Frontier Mail.

Savita, aka Miss 1936, is an amateur hunter while her brother Jayant is an amateur film-maker. Their father, Maganlal, arrested for the murder of a station-master, is defended by their uncle Shyamlal, who is in fact the mysterious Signal X. Shyamlal causes a major train smash-up so as to promote his new airline. He then implicates hero Sundar, son of the railway president, in the crime. Savita overcomes the nasty Signal X, whose henchmen are caught on film by Jayant as they sabotage a bridge. Nadia indulges in extensive fist-fights, set to heavy sound effects, and a famous battle alongside Sundar atop a moving train.