Folded: Hunter Grant Book 3

Notes asking for help folded into tiny origami shapes and found outside a city apartment building, a physics textbook with tiny writing between the lines and a woman who abruptly resigns and disappears. Are the notes asking for help real or is it a game? Hunter Grant, ex-army and with a pragmatic view of justice, reluctantly agrees to help find the missing woman. A high-powered lawyer arrives form the US, and shortly after his meeting with Hunter and Dao a "cease and desist" letter arrives ...