At 2:55 pm one Friday, early October last year, Shehbaz Sharif, the president of Pakistan’s second largest political party, the Pakistan Muslim League-N, was driven into an office of the National Accountability Bureau (NAB), the country’s top anti-graft body.Outside, officers of the paramilitary force and the police arranged in a semi-circle, pushing away curious reporters and onlookers. It was supposed to be a routine probe after which he would be free to leave. Officers would quiz Sharif on a failed clean drinking water project, launched when he was the chief minister of Punjab. However, an hour later, at 3:55 pm Sharif's four-wheeler veered back into traffic, without him. The three-time chief minister was under arrest in connection with the Rs14 billion Ashiana-i-Iqbal Housing Scheme, an entirely different case from the one for which he appeared. It was, mildly put, a rather sudden and unexpected turn of events. Two months later, another prominent PML-N leader, Khawaja Saad Rafique and his brother, were detained by NAB. They were under investigation for embezzlement through another housing society. Before him, Qamarul Islam, who was contesting the general election on the PML-N ticket, was also cuffed by the accountability organisation. In 2018, four senior PML-N leaders were put behind bars. None have, to date, been convicted. "The Bureau is being used for political revenge," thundered Marriyam Aurangzeb, the PML-N spokesperson, soon after Sharif’s arrest. Her party accuses the ruling Pakistan Tehreek-e-Insaf (PTI), which came to power in August, of using the state institution to go after rivals. But the PTI insists it is only fulfilling an old promise, to root out corruption and crackdown on financial crimes, once elected.