A very moving book, and I think potentially very important book.
The gloss: the first son of one of the founders of Hamas grows up full of hatred for his Israeli oppressors, gets caught before he can do anything really criminal, suffers inhumane conditions in Israeli prisons, witnesses Palestinian prisoners torture other Palestinian prisoners, and comes to question the cause he was prepared to fight for. He witnesses the brutality of people in his own culture and comes to think that there may be something wrong with it; seeing that Palestinians were treating each other and the Israelis at least as badly as the Israelis were treating them. He becomes appalled at the universal violence and just wants to make it stop. The Israeli intelligence agency asks him to act as a spy; exposing suicide bombers and violent plots. He agrees on the condition that his information won't be used to kill anyone, only to imprison them. Ultimately this stipulation proves impossible, he's worn down by years of living a double life, and he escapes to the US around 2005 and writes this book about his experiences.
Its moving because of Mosab's empathy, passion, bravery, and his willingness to admit that he had been wrong. Its potentially important because it is an outspoken and clear instance of a person with plenty of reason to be filled with hatred (and the position to act on it) forsaking violence and devoting his life to making peace. Not peace in the sense of a negotiated truce, but a genuine, deep healing that obviates violence. More on this later.
Mosab is truly admirable.