Following years of hard training, Lee Sabre graduates as a Predator, First Class - an instrument of the Galactic Federation, which has conquered and subjugated his homeworld of Terra - once known as the Earth. The Federation sends Sabre and his team on their first space mission, where he is approached by the Terran Underground, an organisation determined to overthrow their alien yoke ... and his decision could have a devastating effect on millions of lives, and the existence of Earth itself.