SONIA Gandhi's 'mystery woman' persona was considerably enhanced last fortnight. Congressmen who had jump-started the oust-DMK demand on the premise that Sonia would campaign for the Congress in the event of elections, soon discovered that they had misread the signals from 10, Janpath. The hardliners' calculation, that a Congress starring Rajiv Gandhi's widow would corner enough seats to form a government at the Centre after the UF's exit, suddenly began to ring hollow.