An old woman is given a tube containing a mysterious liquid by an equally mysterious man. When the man leaves she inhales the fumes from the liquid as she seems to have done many times before and is once again reunited with her dead husband.
While the world is struggling to rebuild itself from a plague eleven years earlier such conduct like "looking back" or open displays of emotion are prohibited by the international "Code of Conduct".
The Code is enforced by government agents like Dan Kagan and his partner Stephanie Sawyer, who are tracing "social terrorists" like Dr. Nathan Seward. Seward traffics in Essence of Life — a substance made of the dearly departed's DNA that allows the living a brief but poignant reunion.
In trying to catch Dr. Seward, Dan decides to visit his late wife, Juliette, who died two years ago, and to talk with her...