The TV series opens with a hardworking, honest cop named Singh (Saif Ali Khan) who gets a call that will ultimately shake up everything he thinks he knows about the police force and his own family. The anonymous call is from a man who we later learn is the long-missing criminal Gaitonde (Nawazuddin Siddiqui). Gaitonde claims to know Singh's father — but that's not the only piece of information that has Singh listening closely. In less than a month, Gaitonde says, Mumbai will be struck by a catastrophic event — which means Singh better listen up to what Gaitonde tells him.