I have no idea why I don't remember much about this story when I started to read this book for the second time.
I felt this story is quite plain and simple to read. You can probably start reading a first few chapters, skip the rest, read the last chapter of the book and you will get the picture of the entire story. It seems another reader has a similar rating and opinion as well :)
More reviews can be found on Goodreads: The Summons.