Lieutenant Colonel Tyler Graven is known as the Demon of Kyoto, specializing in death. After an assassination attempt on a pharmaceutical mogul, Tyler becomes the lead suspect and the target of a 100 million dollar hit. To save himself and clear his name, he must hunt down the killer, a deadly entity known only as The Priest.

Tyler teams up with his former military unit, The Four Horseman, including his brother, crack-shot Corporal Jack Graven, the mysterious Lance Corporal Jin Xialong, and his former flame Colonel Diana Levitas. Once, they were an elite fighting team; now, they’ll find themselves locked in a war with The Church and pitted against the Underworld'sUnderworld’s supernatural forces.

Soon they learn of the legendary Black Muramasa, the only weapon that can destroy immortals such as demons, angels, and vampires. As they uncover the secrets of the ancient black blade-and their heritage-they are faced with unforetold powers and infinite evils. If the Four Horsemen succeed, they may save themselves. If they fail, it’ll cost them their sanity, their lives, and even their souls.

Here comes an action-packed, gun-slinging fantasy adventure that packs the punch of a military thriller combined with high-stakes supernatural intrigue.