A lot happens in the first half. Jagga is an orphan. He rescues a man. Said man - called Tooti Footi (Saswata Chatterjee) - adopts him. They bond. Jagga stammers. Tooti Footi tells him he wouldn't stammer if he sang.Jagga now sings everything he has to say. All is well. But Tooti Footi has to leave.Jagga grows up in a boarding school. He (Ranbir Kapoor) solves mysteries in the neighbourhood.He helps a reporter (Katrina Kaif) investigating an illegal arms affair. His dad has gone incommunicado and he's possibly dead. It's up to Jagga to figure out what the hell is up with his dad.