Aakash Rana (Ajay Devgn), is an engineer who staying with his UK citizen wife Nikita (Kangana Ranaut) in London before his illegal status gets discovered and the courts order him deported, thus crushing his dreams of an ideal life.Four years later, Rana returns with vengeance on his mind and teams up with his former employees Adil Khan (Zayed Khan) and Megha (Sameera Reddy) to wreak some havoc. What follows is a bomb threat on a train and a tensed Railway Control officer Sanjay Raina (Boman Irani) and Anti-Terrorism officer Arjun Khanna (Anil Kapoor) trying every trick in the book to avert the disaster and to apprehend the culprits. Sanjay Raina trying his best to save his daughter Gudi (Avika Gor) and the passengers in the train wherein the train thrown in the mix are police officer Shivan Nair (Mohanlal) and his team of cops, who are escorting a prisoner on the same ill-fated train and the stage is set for thrills galore and an exciting cat and mouse chase.