First off, Josephine Tey died in the early 1950s, so her participation in this project or 'Paranoiac' (an earlier poster comments on Tey's direct participation in both these projects, and "storming" off the set of 'Paranoiac' despite having been dead a decade! Which certainly sounds more like the plot outline for a Hammer film!) must have been facilitated through a seance or oujia board session. In any case, Miss Tey's ghost was certainly justified in "storming" of the set of 'Paranoiac'. The earlier film is an enjoyable B movie which simply bastardizes the novel and has Oliver Reed going completely looney tunes by the end. This version does owe more to Robert Bloch's 'Psycho' than it does to Tey's 'Brat Farrar'. I would surmise that Hammer optioned the film rights to 'Brat Farrar' only to avoid any potential copyright conflicts.
The 1986 Television version of 'Brat Farrar' is much more faithful to the novel than 'Paranoiac' (This is probably due to the direct involvement of Miss Tey's poltergeist!) One major difference is that Farrar & Simon are now played by the same actor. In 'Paranoiac' Reed's brother was played by another actor who had no physical resemblance to him at all -- being that the characters in the Hammer film were no longer identical twins, in fact they were re-named! The lead does a remarkable job in playing both th ersatz 'Brat Farrar' and the cunning, sociopathic Simon. Despite the fact that, at points, the effect of the actor being on screen as both characters looks fake (as it did in many movies, especially flatly lit television movies in those pre, or very early post CGI days) the lead actor was able and adept enough in both performances, that I very often forgot that this was the same man. Another major advantage that 'Brat Farrar' has over 'Paranoiac', is that it was shown over the course of a few episodes (two at least if memory serves me!) and the tension is allowed to build slowly, almost painfully, to it's concluding climax. Despite being a British television film, the look, and feel of 'Brat Farrar' is much more akin to an American TV Soap Opera, and oddly enough, this adds greatly to the surreal, almost claustrophobic tone of deception and imminent danger.
The movies is served well by the fact that plot is allowed time to develop. This also allows the actors to develop and reveal their character's true natures and motives slowly, with all due fairness to the earlier film, 'Paranoiac' didn't have this luxury given the limitations of a feature film's restricted time frame. 'Brat Farrar' features a great cast especially the lead actor. Also noteworthy is Francis Matthews, a good actor who incidentally was featured in many Hammer horror films of the 1950s and 60s. If you can find this film, it is well worth watching!
