Once Upon A Time In Mumbai

!!warning contains spoilers!!!The film opens up with a suicidal attempt by once DCP Agnel Wilson (Randeep Hooda) on pretext of Mumbai Blasts in 1993. When questioned, he bursts up claiming entire responsibility upon himself, quoting 18 years ago when he was posted as the ACP in the mumbai crime branch it was he, who never took serious actions in rise of Shoaib Khan (Emraan Hashmi) who has a major hand in these blasts. Wilson claims that if on those days of Mumbai had he stopped the rise of Shoaib Khan, Mumbai would not had been deluged in the carnage today, then he narrates the time in Mumbai during the days of 1970, when it was ruled by Sultan Mirza (Ajay Devgan), who by his wits had become an underworld smuggler of gold and watches.It is shown that after hit by a flood in his native place, Sultaan Mirza lands in Mumbai where he works in a dock as a porter and smuggles gold items in his mouth, despite earning meagerly he never fails to help the poor and needy and earns their support and respect, slowly he becomes the kingpin of smuggling world in Mumbai. He successfully divides the area among four gangsters peacefully thus pinning the police in the deck who were desperately in search of gangsters fighting with each other. The film shows despite of black activities, Sultan Mirza is a godfather like figure to the people. He is basically a smuggler who has his own principles like he never smuggle drugs etc. He does the wrong things in the right way.Meanwhile focus shifts on Shoaib Khan, who is very ambitious in reaching the top place in the underworld. He wants to be the 'Don' ruling Mumbai under his feet. He is involved in small robberies in concerned areas of Mumbai. In one instance, it is shown that he and his goons beat up a local man injuring him badly and then redirects him at a doctors house. While the doctor and his wife nurses the injured, Shoaib and his goons ransacks the house and flee with jewelery and household items.Next it is shown that Sultan Mirza has a crush on Bollywood actress Rehana (Kangna Ranaut) and eventually the two date each other causing Mirza to invest money on her upcoming films. At that time police inspector, Agnel Wilson, is given the responsibility to stop Sultan's illegal activities. Wilson targets Rehana's films and stop all the films which were invested by Sultan Mirza, causing a downfall in her career. Sultan hatches a plot with Rehana and the two eventually trick Agnel in taking bribe and he gets trapped in newspaper, spoiling his image.Meanwhile Shoaib is getting notorious day by day which worries his father SI Khan and he requests Sultan to take care of him. Sultan visits Shoaib and opens an electronic shop for him. Shoaib works in the shop but never being satisfied, he tells his friends that he wanted to be as rich and respected like Sultan, aspires to join hands and work with him. Shoaib's girlfriend Mumtaaz (Prachi Desai) works in a local Jewelery shop, which Shoaib visits and intercepts him giving him the prized jewelery which he has stolen. In one saga the lady of the stolen necklace recognizes it and she with her husband accuses Mumtaz being a thief and when they reach Shoaib's electronic shop accuses him as thief. In retaliation, Shoaib beats the owner of the necklace and destroys his shop. He goes to Sultan and ask him to take him in his gang. Seeing his ability, Sultan agrees and under Sultan, Shoaib earns the trick and becomes Sultan's trusted aide. He also executes one of the police informers who is there with Sultan acting on Inspector Agnel's words. Sultan's business grow and he smuggles gold in ambulances and public transports.After his success, he goes to Delhi to meet the Home minister for forming a political party giving the power to Shoaib in his absence. The twilight of money and over ambitiousness of Shoaib leads him to do all sort of illegal work, which Sultan has never done. He manufactures poisoned Liquor, which kills many people, accepts contract killings, investing in drug peddling and run extortion rackets and becomes stronger and feared in Mumbai. Meanwhile Sultan returns to Mumbai and finds the truth he at once meet Shoaib and slaps him for his unethical activities. This infuriates Shoaib and he plots for revenge. One day while campaigning for his new party and addressing the people, Shoaib shoots Sultan, who collapses in front of people thus ending a saga of a smuggler who was loved by his people.Narrating the story, Agnel admits later now Shoaib has established an empire and operates from other counties as a king of Mumbai. No political party or power can reach him or harm him. The end shows Shoaib sitting on chair smokes and smiles as undefeated power in the underworld.

Question: Who attemted suicide?
Answer: Once DCP Agnel Wilson