It's so addictive, users become hooked after a single hit, then find themselves quickly trapped in a cycle of self-destruction. Kush is a mysterious new zombie drug that's ravaging Sierra Leone - an epidemic described as the worst in Africa. And amid fears the crisis could destabilise the entire nation - a shocking new twist: the use of ground-up human bones as one of the drug's cocktail of ingredients. A warning, this report contains some distressing images. | Channel 4 News