One of the many things that make The Exorcist arguably the greatest horror films ever made – or simply one of the greatest films ever made, regardless of genre –, is that it has no use for the obligatory final shot suggesting that the evil will continue. On the contrary, it ends on a hopeful, optimistic note; a welcome relief following the ordeal we, characters and viewers alike, have just endured.

Exorcist II: The Heretic carries on as if that final shot had actually been there all along. It's not just that Regan MacNeil (Linda Blair) must go back to dealing with Pazuzu four years after the fact – meaning that two good men died for nothing –; it's how this reencounter comes about.

Once we accept the possibility of demonic possession, everything else in The Exorcist is perfectly plausible. The Heretic, on the other hand, comes up with a "synchronized hypnosis" device that leads to such ludicrous dialogue as "Your machine has proved that there's an ancient demon within her!"

That this line is delivered by a frantic Richard Burton – who could achieve greatness with the right material – doesn't do it any favors. All things considered, the only heresy on display here is what director John Boorman does to the source material (in fairness to writer William Goodhart, his script was apparently rewritten beyond recognition) – I did, however, really enjoy the metaphorical use of locusts, which can go from solitary and harmless grasshoppers to, well, Legion.