Thomas Sankara, the revolutionary leader of Burkina Faso, was shot dead in the presidential buildings in Ouagadougou on 15 October 1987. I was the West Africa correspondent at the time for Radio France International and Libération, based in neighbouring Ivory Coast. The day before the assassination I got a call from Sankara. This was a first. We knew each other well but, until then, his aide had always called me before putting the president on the line. This time, his lively voice took me by surprise.