Guwahati (Assam) [India], December 10 (ANI/ATK): 'Secret Killings' or 'Gupta Hotya' - the darkest phase of Assam, a cruel reminder of what people in Assam have once witnessed and have learnt to live with, without closure. Two-time National Award winner, Nilaanjan Reeta Datta's debut Hindi film 'Shadow Assassins' puts the spotlight on the 'secret killings' of Assam, which marked the darkest period in the history of the North-Eastern state.