Warning: Contains some plot spoilers

I'd wondered from the very first instalment about why Psychoville was running at seven episodes rather than the traditional six. Now I have the answer. Messrs Pemberton and Shearsmith's love of film and all things Hitchcock-ian is so great they penned a brave homage to one of the big man's finest, Rope.

And it was good. Very, very good.

The ambitious production of this 'special' episode saw events happen in real time as the footage was taken in one continuous shot ala Rope (actually, the technology in Hitchcock's time meant that film was shot in ten-minute takes - watch the excellent documentary on the DVD of the film included in the Hitchcock boxset for a fantastic insight into how that was made).

As the brief documentary on the Beeb's Psychoville website shows, this involved a herculean effort from Shearsmith, Pemberton and long-time collaborator and friend Mark Gatiss, plus the crew, working as stagehands and carrying out the usual filming and audio duties. The results were captivating, the actors' time on stage for the genesis of The League Of Gentlemen no doubt helping them to nail their roles in what was essentially a televised play, shot 'as live'.

The plot was all about around creepy serial killer David and his arguably even creepier mother Maureen. Having murdered another of the Murder Mystery Party guests in his own home, dumping him in a chest to hide the evidence - just like in Rope - things go awry (after the pair have had a good old dance to Black Lace's Superman first).

A man claiming to be Chief Inspector Griffin (played by Gatiss) knocks on the door, explaining he is investigating recent murders in the area. Confusion abounds as Griffin thinks David is the now deceased house owner and David and Maureen think Griffin is really a copper, whereas in reality he is actually auditioning for a role in the Murder Mystery group - or so he thinks. Needless to say, Griffin's time is up, unless he can leave before noticing the dead body hanging on the door, that is.

There was an element of distraction in watching this episode with myself left pondering such thoughts as 'how did they do that?', 'the camera movements are excellent', and 'just how great a trio are those actors to nail their lines so perfectly without the need for a another take?'. But really this all just added to the excitement of the viewing experience.

This was bold, unique programme making and with BBC One taking the similarly brave decision to air Torchwood over a single week, these are exciting times for the broadcaster. Perhaps the credit crunch has played a part in these positive steps, forcing writers and producers to think up new ways to get creative and hold our interest? Whatever the reason, this past week has seen some of the most interesting television of the year.

This week's big revelation was that David turned to knocking off lives because he feels guilty for having killed his father years ago with a sleeping pill overdose. Except he didn't and it was actually mother Maureen who bumped him off, having been poisoning him for months before.In the time-worn tradition of Hitchcock, behind every psycho killer lies a deeply disturbing family past.

The final shot of the episode, a close-up of Maureen smiling while David strangles his latest victim, told us all we need to know about this pair.

David struggles with his demons throughout the episode, saying at various points that he wants the killing to stop. The suggestion was clear. Maureen won't let him. She loves her son, that's for sure, and she's created this monster by allowing him to live a lie for all these years. She'll be damned if she's going to let him stop it all now.

This episode will rightly be viewed as a standalone episode, a flight of fancy for the boys that love their cinema. It wasn't as funny as the other episodes thus far, focusing on the drama of this comedy-drama series. The episode's own restrictions also meant there could be no big set piece which are the sources of much of the show's broader comedy, such as in last week's superb jungle gym fight.

Not that it matters. This was all about experimenting within the boundaries of television while also successfully managing to flesh out the show's creepiest characters. The series will have funnier episodes. It will be a hell of an achievement if it has better ones.

Check out our review of episode 3 here.