Train Heartnet, reformed assassin turned bounty hunter, also known as Black Cat, comes to the aid of a troubled boy seeking revenge for the death of his parents and is forced to confront his own vengeance-laden past. Meanwhile, Rinset forms a shaky new relationship with an old enemy.

The final stage of the battle begins! Now that Train and the Sweepers have reached Creed's hideout, there is no turning back. But for Train, it's not about avenging Saya's death anymore. He is risking his life to capture Creed as a member of the Sweeper Alliance.

"Train Heartnet, also known as Black Cat, was an infamous assassin for a secret organization called Chronos until he abandoned that cold blooded existence... The Chronos assault team... find[s] themselves battling a beast created by nanomachine technology. Sensing danger, Train appears on the scene. But instead of taking sides, Train has his own agenda."--Cover p. [4].