Most shows over the years have done a Halloween episode - they must be almost as common as Christmas episodes. Quite often these are tongue-in-cheek or at least a bit off-beat. Not so here. This is (pardon the expression) a full-blooded horror movie that produces an effect akin to that of a 1970s Hammer film. The startling murder in the opening scene is just the beginning. Soon we're involved with a series of gruesome murders that shock even the forensic team, a social network of Wiccan yuppies, and a charismatic stage magician who makes David Copperfield look like a vaudeville conjurer (Richard E. Grant plays this part like he was channeling Christopher Lee). For light relief we have a sub-plot (or is it?) about Dalziel undergoing hypnotherapy to try and kick the cigarette habit. This is utterly gripping stuff.