In Crossing the Rubicon, which was a three-year project, George Christie uses the metaphor of "crossing the Rubicon" to describe personal journeys and irreversible decisions. The book covers a variety of topics related to the outlaw motorcycle club culture, including: His complex relationship with the late Sonny Barger, the long-time public face of the Hells Angels; The escalating "war" between the Mongols and Hells Angels in the late seventies, which included shootings and bombings; Internal club issues, such as the death of a personal friend; and the challenges and experiences of leaving an outlaw club and being considered "out bad" or exiled.

George Christie felt compelled to respond to attacks on his character and create an accurate historical record of his life, which led to the writing of this book.