In the world of Star Trek the term Prime Directive refers to the principle of non-interference. This means that ships of Starfleet are prohibited from interfering with the normal development of the worlds they encounter. In Star Trek: Prime Directive, Captain Kirk is accused of violating the Prime Directive and is subsequently relieved of command. However, an investigation is conducted (with the astute Mr. Spock as one of the investigators) and yields some interesting results--and a strange, new alien life form.The audio version of this book is an abridgement and contains music and sound effects. It is fitting that James Doohan narrates the story as many of the events are told from the perspective of Montgomery Scott. I have not read the book, but I did listen to the audio version twice and got more out of the story the second time I heard it. In short, Star Trek: Prime Directive is a very good story to listen to in your home or car.