Chill Factor

Hennessey and Yellich are looking for a Mr Big - A corpse is discovered in the middle of the city of York. Male; no identification. Shot. And tortured before his murder. A professional hit, by the look of it. Gradually people talk; hints are dropped; and trails appear all leading to a man with no record and who has never been inside a police station. But the police know him he's connected to another unexplained death. And another. And a few more.