One assassin. One virus. One chance to stop the end of humanity.
Five years ago, Ryō killed his Yakuza partner Niko—after watching him murder the woman he loved. With her final breath, she made him promise to live for himself—words he’s never fully understood.
Now living as Hiroshi Ichihara, a quiet college student, he’s buried his past. A second chance. A normal life.
And for the first time, he believes he might be able to keep that promise—until a first date shatters everything.
Forced to reveal himself, Ryō discovers the impossible: Niko is alive.
Worse, he’s united the Yakuza clans and engineered a CRISPR virus that could destroy the world. Only one person can stop him—the assassin Ryō swore he'd never become again.
But there’s a price. Every kill awakens the darkness inside him, the bloodlust that made him Tokyo's most feared killer. The more he fights, the more his humanity slips away.
With Ayako Yanagi—a brilliant doctor he doesn’t trust but can’t afford to lose—as his only ally, Ryō must return to Tokyo’s underworld to infiltrate Niko’s genetically enhanced army and stop the virus before it’s unleashed. But defeating his former brother-in-arms may cost him the one thing he’s fought to keep: his soul.
Can he save the world without becoming the monster he fears most?
Content Warning:
This novel contains scenes of intense violence, combat, and interrogation, including a brief depiction of waterboarding, as well as a sexual scene.
