The Last Watch: (Night Watch 4)

While on holiday in Scotland, visiting 'The Dungeons of Edinburgh', a young Russian tourist is murdered. As the police grapple with the fact that the cause of the young man's death was a massive loss of blood, the Watches are immediately aware that there is a renegade vampire on the loose. Anton - the hero of the Night Watch trilogy - is detailed to this seemingly mundane investigation, but begins to realise that there is much more to the story than a wildcat vampire and a single murder, and discovers that a team of unlicensed Others are hunting for a fabled magical treasure, hidden in the sixth level of the Twilight by Merlin himself...