Most books try to be imaginative in creating a world, a story, characters, a plot, ... and at the same time try to be as realistic (no: believable) (no: true) as possible in describing this world, unfolding the plot, writing dialogues, and real people. 
 Even Lord of the Rings- as fantastical as it is- is believable and true in it's creatures and their reactions and the interplay with the world they live in. 
 This story (actually intertwining storylines) is as imaginative and realistic as can be. 
 I loved loved loved it! 
 btw. when there's ever an audiobook which adds extra value it's this one. The reader/actor was as cool as the McNulty/Bunk-talks in The Wire