(When I said tomorrow, I obviously meant the day after the day after tomorrow. You knew that.)

The third film is where things begin to click and is my personal favourite. It is utterly charming – Aunt Marge is still floating in the sky when we see Harry leave the Dursleys; Stan looking around the corner of the bus to where Harry can see the dog; the fun of the Whomping Willow used to show the passage of time throughout the film (the film may only be a few hours, but it relates to 8 months); the use of moving wizard images of Sirius Black on the newspaper and the posters – and the film is infused with humour and fun: Tom at the Leaky Cauldron; ‘Room Service!’, the boggart scene; ‘You tell those spiders, Ron.’

The introduction of two characters that are so endearing and so linked to Harry’s family, in the forms of Sirius and Remus Lupin, also make this film a particularly warm film. It allows the film to connect with us via the characters. The actors are all very enjoyable – Oldman, Thewlis, Snape, Smith – but not everyone is perfect. Gambon is okay, but I’ll always see Harris as Albus (even though Gambon seems to adhere to the more flaky character of the book version of Dumbledore). Julie Christie has a very silly accent as Rosemerta. And there is the bizarre appearance of a large black boy in Harry’s class that we’ve never seen before who gets all the ominous exposition lines in a scene. What’s worse, he delivers them really badly, and he has an abnormally low voice for someone his age, which makes it stick out all the more.

The most wonderful aspect of this film is the visual delight and sense of magic that pervades the whole fabric of the film. Cuaron uses CGI wonderfully, to illuminate a world that is like our own but is decidedly not. There is always something to remind you in the background that this is not our world, and that is wonderful thing. The films should exude this fantasy element, not as the defining characteristic but as part of the scenery. One of the worries I have about Order of the Phoenix was a quote from the director David Yates, saying he was brought in to make it more real. That is completely missing the point of the magical world that JK Rowling has created. If I want a searing political drama, I’ll watch that. I want to watch a film about a young wizard and his battle against evil.

The fourth film is a cracking little thriller – which means that lots of things have to be dropped from the book, but that is inevitable and okay – that is a lot of fun, even if it lacks a lot of the magic of Cuaron’s visual stylism. Everyone gets better in the acting stakes, and there is the sense of darkness that we are promised. However, having a film where someone escapes from Azkaban and not explained AT ALL after the film where the whole point was about how impossible to escape from there seems that the thriller element overtook explaining all the nuances that are in the book. In fact, it would seem that if you compare the book and the film, the film will tell you which parts aren’t important for the final book because of their absence. If it’s not important enough to be in the film, then it doesn’t matter to the denouement.

Which brings us up to date, in preparation for the fifth film, ‘the darkest yet’. As an obvious fan, I’m looking forward to it, so will enjoy it anyway. I just hope that it will be a good film in its own right. I’ll share my thoughts when I’ve seen it.