This was a fun book full of puzzles and racing against a faction to solve The Dragon Box....a 150 year old mystery. 

I didn't read book 1 but I didn't feel (?) that I needed to, to enjoy this one. Mike became a savant after a TBI (traumatic brain injury) and now he can solve the most complex puzzles. He gets invited to Japan to a contest to open the box (a contest that only happens every 12 years)...a contest where people have died or disappeared while trying. 

I loved the pace of the race through Japan. I loved the drawings that accompany and of the puzzles. I liked to see how Mike thought through things and the help he had throughout.