The Darkness of Light

The Darkness of Light begins with a building site and ends with a witch-burning, and the distance between those two things is the episode's subject. Bodies are found during the digging of foundations at the Norton Hotel, and Carol Jordan is sent to establish whether they are suspicious or merely old — a legacy of the hotel's previous life as part of the local abbey. Then the hotel burns to the ground, and what began as an archaeological question becomes a murder enquiry.

Hill is brought in when it becomes apparent that someone is killing in a manner that Norton has not seen since it burned witches in the Middle Ages. The episode's institutional comedy is provided by John Brandon, who has nothing to brief the press with beyond a psychologist's theory that the same killer could be reaching across five centuries of murder, and who is not pleased about it. Tom Chadbon had been playing that exasperation since 2002, and it is one of the show's more reliable pleasures.

What makes the film distinctive is its register. Wire in the Blood was usually a procedural with a psychological method attached, but this is folk horror with a police budget: the ruined abbey, the fire, the village with a long memory, and a violence that is explained historically rather than psychologically. Nicholas Laughland, who directed two of the first series' parts, builds the episode around the visual contrast between the new hotel and the older stone beneath it, and it is the only instalment of the run that looks like this.

The reversal of roles is worth noting. Jordan, not Hill, is the one who has to sell an implausible theory to a superior, and she does it badly enough that Brandon's scepticism is a real obstacle rather than a running joke. Hermione Norris plays the frustration of an officer arguing from instinct while outranked, which is precisely the position Hill occupies in every other episode, and the symmetry is deliberate.

The weakness is that the premise is thinner than the atmosphere. The five centuries of murder suggested by the synopses turn out to be much more local, and an audience watching closely will find the historical frame decorative rather than structural — a strong coat on a serviceable body. The title promises more than the third act delivers.

The episode drew 7.20 million, its best figure of the 2004 series, and it is easy to see why: it is the one where the show changed its clothes. It is not the most representative instalment of the run, and it has very little to do with the series' central argument about Hill's method, but as a standalone piece of television it is the most atmospheric thing in the first three series.