First, getting a bit of context about the Sri Lankan civil war is essential to fully understand what is going on. 
As for the actual review, while the book started out a bit slow, it picked up and quickly became difficult to put down. Trying to guess if Maali will side with Sena or Dr Ranee is something on your mind throughout the book, and each new piece of information is unexpected yet cohesive. Karunatikala’s interpretation of the afterlife is well-developed and interesting and offers insight on how those who are dead continue to influence people who are still living. 
Overall, it’s a fantastic read.