It was a 1 am "coup" that set in motion cataclysmic changes in the Central Bureau of Investigation (CBI), the country's top investigating agency, caught in a one-of-a-kind battle between chief Alok Verma and his deputy Rakesh Asthana. Around 12:45 am last night, the preps started with the police cordoning off the CBI building in Lodhi Road in south Delhi.