Perry Helion, an agent for the Defense Advanced Research and Projects Agency, joins a friend on a salvage expedition in the Bering Sea. The salvage firm, however, inexplicably kills a Russian official before trying to make Perry the next victim. After an escape that nearly drowns him, Perry discovers the salvage company is only one element of a veiled organization named Paracelsus operating in the hidden channels of the deep state. Perry learns Paracelsus has developed a targeted bioweapon that can kill based on specific DNA profiles — like those of the President and his cabinet. Aided by his DARPA colleagues and a rogue CIA counterintelligence team, Perry must thwart the Paracelsus plan while never knowing who can be trusted.