While the occupation of Earth continues, MinSha mercenaries under the command of Major General Drehnayl have assaulted human-held colonies in the outer rim, wiping them out. With the famed Four Horsemen nowhere to be found, the Mercenary Guild’s attempt to instill fear and subvert humanity is perilously close to reality. Tasked with finding the MinSha is Jessica Francis, Earth’s first Peacemaker, but the odds aren’t in her favor. Jessica realizes that finding Drehnayl's forces isn’t enough - she must do something to stop their atrocities and end their reign of terror.

Heir to one of the leading "Four Horsemen" mercenary companies, Jim Cartwright is having a bad year. Having failed his high school VOWS tests, he's just learned his mother bankrupted the family company before disappearing, robbing him of his Cavalier birthright. But the Horsemen of eras past were smart - they left a legacy of equipment Jim can use to complete the next contract and resurrect the company.

The plot by the Galactic Union’s Mercenary Guild against the Four Horsemen has culminated in an invasion of Earth. Faced with an overwhelming force, the human mercs had no choice. They’ve fled, leaving Sansar Enkh to go to the Mercenary Guild headquarters on Capital Planet to stand trial for humanity. On the run, Jim Cartwright and Nigel Shirazi have travelled to the Winged Hussars’ secret base of New Warsaw, in an effort to convince Alexis Cromwell to join the fight, while the other mercenaries who escaped the fall of Earth have gone to the perceived safe haven of Karma.

The Omega War is in full swing. Earth has fallen to General Peepo’s army, and the surviving human mercenaries have taken refuge at the hidden Winged Hussars’ base in New Warsaw. On Earth, the defensive forces fight to keep the hearts and minds of their fellow humans, but Peepo’s plans are slowly converting the people to her way of thinking, and the Mercenary Guild troops continue to root out the forces arrayed against them.

As a crumbling Galactic Republic falls to the relentless assault of a merciless foe, so begins the rise of an enigmatic emperor intent on saving a corrupt galaxy-spanning civilization from itself…and from something much darker that lies beyond the reaches of the known. Just as the reins of power fall into his iron-fisted grasp, an assassination attempt by a hidden cabal within his own inner circle jeopardizes every plan he has set in motion for his Dark Legion, his Imperial Navy, and his ultimate conquest of the stars. But the assassins have no idea who they're actually dealing with.