Two things appealed to me about this book. First, I am fascinated by animals learning human language, had read about Nim Chimsky long ago and was fascinated by the use of sign language with animals. I appreciated the notes at the end leading to research backing the novel actions and to the comment that most of the ape - human conversation was based on real conversations, although the book was fiction.

Second, it was a real page turner with twists and turns. Some events I could figure out ahead and some surprised me, a nice balance.