The nkondi are the most powerful of the nkisi. They were used to identify and hunt down unknown wrongdoers such as thieves, and people who were believed to cause sickness or death by occult means. They were also used to punish people who swore false oaths and villages which broke treaties. To inspire the nkondi to action, it was both invoked and provoked. Invocations, in bloodthirsty language, encouraged it to punish the guilty party. It would also be provoked by having gunpowder exploded in front of it, and having nails hammered into it. These fantastic Congo nail fetish figures are just one small, wonderful part of the impressive collection of images you can view at the content-rich, gratifyingly obsessive Rand African Art, a site stuffed with nice large photos, lots of lovely, lovely links, and all sorts of intriguing nooks and crannies inviting exploration.