Cochin Express
Cochin Express is a 1967 Indian Malayalam-language thriller film, directed by M. Krishnan Nair and produced by T. E. Vasudevan. The film stars Prem Nazir, Sheela, Adoor Bhasi and Sankaradi in lead roles. The film had musical score by V. Dakshinamoorthy. The film was subsequently made in Kannada as Bangalore Mail, in Telugu as Circar Express, in Tamil as Neelagiri Express, and in Hindi as The Train. Plot 
Police Officer Rajan who is in charge of investigating a murder that happened in 41/42 Cochin Express (present day Alappuzha-Chennai Express) from Madras to Cochin. Unni Kannan Nair who was a passenger in the same compartment where the murder happened and also he is the only person who saw a lady passenger that is suspected behind the murder. 