Making a great sequel is hard; making a great threequel is harder.
The difficulties arise for a lot of reasons. In How to Sequel, we discussed that a sequel needed a reason to exist, whether that was to continue a story or to explore a world that already exists. Well, with a threequel the usual reason it exists is to resolve a cliff-hanger or because a director needs something a studio will green light no questions asked, and usually a second sequel to an already popular two movie franchise will do the job (i.e. Men in Black 3, Rush Hour 3, and, alas, The Godfather Part 3). It can also be a bargaining chip to get a pet project made. As much as I enjoy The Dark Knight trilogy I am very aware that Nolan only made them to get the cash/kudos/freedom to make Inception and Interstellar (This is probably more evident with Dark Knight Rises than with Dark Knight).
To break it down, class, there are three types of threequel. First, there are threequels that complete a story. Each movie follows on from the one before to create a vast three film story i.e. Return of the Jedi, Dark Knight Rises, Back to Future 3 etc. With these movies the previous movies need to be seen in order for the grand story to make sense and the third film resolves a cliff-hanger from the first sequel. With the three examples above, they follow superior movies and can each be described as flawed. That’s not to say they’re bad (my love for Return of the Jedi is well-known) but they are not the same level of quality as their predecessor. Of course with this threequel you could run afoul of Spider-Man 3 Syndrome, in which the studio interferes and your director and actors seem to have grown tired of the series. Not a good recipe for success.
There are the stand-alones. These are movies that will retain a main character and some elements from what came before but you can dive straight in with very few issues. Movies like Indiana Jones and the Last Crusade, Mad Max Beyond Thunderdome, Die Hard with a Vengeance, Goldfinger, and Batman Forever. These movies can escape a lot of the judgement of the story trilogy as you don’t need the movie before it so can avoid comparisons. However, if they are awful they can be removed from your watch list as they, lacking an ending to a trilogy, are obsolete.
Finally, there are adaptation threequels. You cannot hold Return of the King, Harry Potter and the Prisoner of Azkaban and Mockingjay up to the standards you would hold the above because they exist based on the story’s success in a different medium. They don’t face the issues that the Back to the Future trilogy faced as they already have a built-in reason to be made and a built-in audience who want to see them.
So how do you do it right? You finish a story already in progress in a satisfying way. Or you create a new story with some familiar elements placed in a new environment. And at all times you only make a threequel because it needs to be made. When a movie has been made solely for cash it shows in every frame — every tired, tired frame — and sometimes two movies is enough.
Next week, we’re looking at prequels, because every journey has a beginning, usually with fan service-y cameos aplenty.