In this exclusive edition of HT’s The Interview: Case Files, former IPS officer and Enforcement Directorate director Karnal Singh revisits some of the most high-stakes investigations of his career — from the Delhi serial blasts and Batla House encounter to the Indian Mujahideen terror network and major ED operations. Singh reveals how a cryptic phone call became a crucial breakthrough in the investigation into Delhi’s serial blasts, helping investigators trace a terror network and solve 18 of 42 cases. Watch the full candid interview here