This is the second book in a series, so you are going to want to read the first book in the series Fear University to understand this world and who/what the main characters are fighting/fighting for.
Winter in the Alaskan North has short days and long nights especially for 65 days of the year, which is perfect for the Aswang to hunt and kill and challenge. This is where Ollie and her friends have been stationed. They need to protect the humans from the Aswang, so each night they along with the other hunters will stalk, hunt and kill. But the fight for survival does not begin and end as one enters and leaves their base, murder is about to happen inside the walls as well, so there is no where that they are safe they always have to be on gaurd, but they only need to try and survive for 65 days, that's doable right?
I liked this one better than the first, I found that this one was darker, more twisted and at times fairly graphic when compared to the first book in the series. Additionally, I did not feel like this book had any down time in the story, as it is the Killing season, there are lots of hunts and killing that need to be achieved as well as trying to figure out what is going on inside the base walls. It was also interesting the family dynamics that are played up in this book that you do not really know who Ollie should trust and really is there more danger in the house rather than outside it.
The first book also lacked having more than one point of view, so it was really nice to have Sunny's POV in this book to give a change up from Ollie's very negative one (really she is doom and gloom most of the time). Sunny was also able to give a different perspective on what was happening and how Ollie is perceived by those around her even her friends. For lack of better words having Sunny tell part of the story was very refreshing in this book.
If you are a fan of books with sexual tension well, The Killing Season has is in spades between Ollie and Luke. You will keep wanting to have them interact more and more as the book goes on as eat time is more "heated" than the last. If you are wanting more of a love story/crush then you have Sunny and Hatter, so Collett does a good job of covering both these aspects but at the same time having those relationships secondary to the main premise of the book.
I think my least favourite part in this book is that I was able to figure out the big twist way before it was revealed (which is the same problem I had with the first book in this series) and I was just waiting for the characters to catch up to what I had already figured out. However, this series as a whole so far has an interesting premise which overall does make for an interesting read.
I am enjoying this series and it is nice that Collett has improved from the first book to the second, which makes me have high hopes for the third, which I am planning on picking up soon.