I’m noticing this common trend in trilogies, where the third and last book of the series is extremely different than the first two books. The story is different, the writing varies, and generally, the setting is different.

Not only am I part of the Third Book Syndrome Club, but best sellers like The Hunger Games and Divergent are also guilty of this.

Just a heads up, there will be spoilers from all of these as I’ll use them for examples. If you haven’t read them, but plan to, stop reading now. Unless you don’t mind reading minor spoilers.

So, Third Book Syndrome.

The Hunger Games :
Book 1. Katniss is a strong, independent girl who fights in an arena to save her sister.
Book 2. Katniss is a strong –  if somewhat suffering from a mild case of PTSD – independent girl who fights in an arena to save Peeta.
Book 3. Katniss is an absolute mess, there’s no arena, and weird shit goes down. The setting of District 13 is brand new to this world. A whole new cast of characters are introduced, and the overall feel is different than the first two.

Divergent :
Book 1. Tris joins Dauntless and trains to become one of them, living in a city surrounded by a big wall. They’re not told much about the outside world, just that it’s dangerous.
Book 2. Shit happens, Tris and Four spend nearly the entire book running from one place to another, still within the walls of the enclosed city. So while the scenery changes between factions, it’s still within the same world we lived in in book one.
Book 3. They go outside the wall. There’s a whole cast of new characters introduced, and there is a really, really, really, shit explanation of why they were locked in the city to begin with. (Can you tell I wasn’t a fan of the third book?)

The Institute :
Book 1. Allira finds herself in trapped in the Institute, doing whatever she can to protect her brother. Even if that means working for them. Three quarters of the book is set in the Institute.
Book 2. Allira escapes, but that’s not enough. Her family and friends make a plan to take the Institute down. Three quarters of this book is set in a new setting – the Resistance compound. The rest, is set in the Institute.
Book 3. The Institute makes an appearance a total of three times in the whole book. Allira isn’t the strong girl she was in the first two, and she’s lost, unsure of what she should be doing with her life. She does what those around her ask of her without questioning whether she should. With the help of new characters, she fights to find herself once again. There is a major romance plot line in this book, something that was very minor in the previous books.

All of the last books of each series feature a new setting, new characters, and major character arcs… well, except for Divergent. Tris didn’t learn a damn thing or change at all in three books. (but the new characters and new setting thing is true)

As a general rule, by evidence of reviews, the third book in a trilogy is the least favourite.

When I released book three of The Institute Series, I was so excited for people to read what I thought was my best work. It didn’t even occur to me that my new, improved, but different vision of where Allira’s life led, might not sit well with my readers who loved the first two.

The people who absolutely gushed over book one and two, found the third to be too different. They still enjoyed it, sure (or so they said in their review), but of the three, it was their least favourite.

I could say the exact same for my two examples. Mockingjay was my least favourite book of the Hunger Games series, and I barely made it through Allegiant, book three of Divergent.

So, what is it about book three that we as authors feel we need to mix it up? 

Could it be that in The Hunger Games, there was an arena in book one, an arena in book two … did we really want to see another arena in book three?
Okay, so all you die-hard fans out there will argue that when Katniss and her troop try to storm the capital, they are in arena like circumstances with the pods and weird mutts that are after them. But it’s not the same thing.
If there was another arena in book three, would the reviews be saying, “How many times can a government try to kill one girl? It’s the exact same plot as the last two!? I’m bored!”

Book two and three of Divergent were scattery, at best, but the different setting in the last book was necessary to resolving the questions everyone had been asking for the first two books.

In the Institute, Allira’s life had changed so drastically in between book two and three (there’s a massive eighteen month gap in between the books), it would only make sense that she would be meeting new people and forming new bonds. The first two books were about Allira’s fight against the Institute, the third was about her learning to be an adult.

Growth is an important part of writing. Characters need to grow and learn lessons, or you get to the end and kind of ask “well, what was the point of that?”

 How much change is too much, and how much of the same is not enough?

Why do you think people aren’t falling in love with trilogy endings?

Listing off other trilogies that I’ve read that also follows the different story arc for the third book include:

The Mara Dyer series (loved the first two books. The third just went weird.)

The Maze Runner series (although, this one lost me at book two, if I’m completely honest.)

The Matched series (but to be fair, I’d say of all of the books on my list, this one is the one that remains most true to the first two.)

How do we prevent the different story arc, but still show growth within the characters/community, without getting repetitive by using the same plot as the previous books. Or is this what readers want? They fell in love with book one and two for a reason, right? 

If anyone has the answer, I’d really like to know, because after mapping out my next trilogy, I’ve noticed it follows the same pattern.