A great balance between a simple and complex thriller! The humor, the relationships and this mysterious small town add that little extra to the book. I think we don't have to argue that the plot was well down. And yes, as the reader you can solve something but the final twist will be a suprise. I really enjoyed our main characters and I get that if you don't like them, you won't rate this book a 5 star. 
For me this was quite easy because all the boxes (characters, plot, writing, enjoyment) are ticked!