Here's a small portion of what happens in the story (without trying to give away too much about the previous 4 books): Kaylee is a banshee - she gets the urge to scream when anyone around her is dying. When she screams, she can keep their soul from moving on, and if she's with a male banshee, they can put the soul back into their body.
But it comes with a price: when one is saved, another will die.
Kaylee knows all about borrowed time; she died when she was 3 years old in a car accident and her mother and father saved her - but her mother died in her place. Now, it's Kaylee's turn to die, as she's dying on the day that her mother would have died if they didn't upset the natural order of life.
Throughout this novel, Kaylee realizes what's important to her. She only has 6 days to live - she's going to make the most out of it and not do things that she doesn't want to do. Now she's reevaluating her life and finding out that there are people she can and can't forgive for past actions, and she's going after what she wants rather than what she thinks other want her to do.
Again, this was an amazing book. There are so many surprises and, yes, there is a cliffhanger at the end of the novel, but I know that Vincent is working on the next novel right now and it will hopefully be out very soon! I can't wait to see the ending of this amazing series and I hope everyone will go out and read these books!