Sergeant Clark was the head of the St. Louis' precinct's gang unit where several gang members had been electrocuted. However, when Myka and Pete began their investigation, he was away on leave. He turned out to be the one who had found the Spine of the Saracen, which Jack Secord had hoped to entomb with himself. The rage it provoked was, in Clark's case, directed against gangs, but as with all users except Pete, he was eventually 'consumed' by the Spine itself, and died.