Blood. Lots of blood.Did you know this book was assigned reading in some places before the movie came out? True story. I can see why, too. One generation pitted against another, good intentions gone awry, and people seeking their place in the world. It also happens to be accompanied by vicious murder, which probably keeps the young people interested. It also shows the trauma of PTSD in a time before that condition had a name.This is not the Rambo who appears in Rambo 2-4, or even in the ending of 1 (also called First blood. If you have the chance, watch the alternate ending to 1 - it's a lot closer to the book, and a lot more fulfilling, if depressing.This book is brutal, but, then, so is war. Maybe that's the point.