Communication satellites fail due to massive data intrusions and ex-hacker Paul Trimble finds immovable data intrusions in his computer, in the computers of US military and spy satellites and in computers at the Deep Space Network. A very sophisticated denial-of-service attack threatens US military power and chaos is imminent. A Task Force is set up to locate the source and stop the intrusions but they find that the intrusions use tricometric coding far in advance of any known system and have accessed our digital world through the open back doors of our commsats. Dr Avril Stone proves that the intrusions originate in deep space and are a digital form of DNA, indicating extra-terrestrial intelligence. John Craig confirms that this intelligence is based on a triple string DNA with self-replicating capabilities. The Taskforce cannot stop it and the US defence system is powerless. Chaos is imminent.