Richard MacDuff is somehow neglecting his girlfriend Susan due to his excess of work, and leaves a message on her answering machine that he immediately regrets. Richard then decides to break into Susan's apartment to erase the message, but he is caught in the act by the holistic detective Dirk Gently. When Susan's brother is murdered, Dirk decides to act on behalf of Richard, even if the police is not really suspecting him.

This book gets better every time I read it. I understand it is hard to keep up with the plot and characters, so I would suggest a new reader to just enjoy Adams' marvellous imagination and hilarious character development on a first read. The author is extremely quotable! When you think you understand what happened, then go read it again because the story eventually makes sense and you will be able to laugh twice as much.