Good things first: The most amazing characters are the antagonist. It shows how people use religion to manipulate others into doing things which they would otherwise won't do.
The chapters are nicely curated - not too long and not too short.
The excerpts from MahaBharat are an interesting additon. Infact sometimes fels more interesting that the original plot.
The language and tone is nice and easy to read.
Writer kept introducing twists in the 2nd half which kept you hooked to finish the book
Now the negatives: The plot mixes many genres such as detective, history, supernatural, nuclear physics, archeology, mythology, and what not.
Atleast the 1st half of the book has been spent in proving the historicity of mahabharata and existence of nuclear weapons in ancient India. At best it seems a forced effort to make the reader believe that it is the only truth which west has been trying to hide, at worse it feels like propaganda. The protagonist isn't given a strong reason for his run and quest and feels forced to go with the flow instead of thinking. Sometimes writer was so indulged in provng the myths that it felt like a narration within a narration or a history lecture, if I would want to know about history I would pickup up a history book not fiction.
Overall, a good one time read but to be read with caution keeping in mind that it is not a reference for history but rather a work of fiction merging multiple histories and theories.