The final episode of A History Of Horror, titled ‘The American Scream’, somewhat mirrors the rather cold and less emotional output up for discussion. Gatiss’ involvement is more detached than the warmth he displayed in the previous two instalments. In fact, he takes a more sociological, almost academic, approach to the Romero films; studying the turmoil of American life in the two turbulent decades.

To be frank, some of his conclusions and assessments are all a bit Film Studies 101 – his personal interpretations are intellectually thin and obvious. But this is not an academic show, and nor should it be. So it was a tad odd to hear Gatiss go from heartfelt effusion to cold historical context, regardless of how relevant.

The previous two episodes were also home to some beautiful and exotic location work, but this is sadly lacking here. Again, this is simply a mirroring of, arguably, a duller, less naturally visual time in the genre. The Bates motel from Psycho and the house from Halloween pall in comparison to the Gothic locales witnessed previously.

Although the big hits of the time are examined (The Omen and The Exorcist, for example), as one would expect, Gatiss also takes in the more powerful and meaningful movies. Romero’s Martin is a welcome addition (and could have done with more analysis as it stands the test of time much more so than its contemporaries), as is the work of David Cronenberg – a true “horror” visionary.

‘The American Scream’ is a disappointing end to an otherwise top-notch series. Less personal, less engaging and, ironically, less colourful (considering he looked at many black and white films) – much like how the horror genre panned out last century.

Airs at 9pm on Monday 25th October 2010 on BBC Four.