Chicago, 2071: a city divided by corporate and government districting. Supplantation, the insertion of animal genes into human DNA, was once the most sought-after elective procedure in the nation. However, due to its horrible side effects, it was quickly banned and vilified, relegated to the black markets of the underground. Now, the city is beset by a serial killer who uses his supplanted genes to commit his crimes, and supplantation is once again thrust to the forefront of everyone's consciousness. Meanwhile, amidst the media and political firestorm, corporations have begun pushing new genetic research, setting off a chain reaction that could threaten the lives of unsuspecting citizens. Zen, a legal executive for a private security firm, and Mik, an Army veteran turned butcher's apprentice, must face a hidden world and fight a powerful enemy that will stop at nothing in pursuit of scientific progress.