As the trail of blood and honor gets deeper and longer, corruption and double crossings abound. Two considerably evil and ambitious forces, previously teamed to finally kill the vengeful samurai Ogami Itto, clash in the torrential rains that continue to pound Edo. Determined to be the first to reach Ogami Itto and his son Diagoro, the shogun's own poisoner waits in a temple where the samurai and his toddler boy left their cart, reflecting on the path that has led him to this point, and brewing his most deadly poison. And the fiery Retsudo won't be stopped in his quest to kill Ogami, however now he must be wary of the poisoner's crafty ways. Meanwhile, the Lone Wolf and Cub enlist the aid of a tailor to help them prepare for what could be their last stand! There's something in the air, and it smells like death!

Kazuo Koike is a prolific Japanese manga writer, novelist, and entrepreneur. Early in Koike's career, he studied under Golgo 13 creator Takao Saito and served as a writer on the series. Koike, along with artist Goseki Kojima, made the manga Kozure Okami (Lone Wolf and Cub), and Koike also contributed to the scripts for the 1970s film adaptations of the series, which starred famous Japanese actor Tomisaburo Wakayama. Another series written by Koike, Crying Freeman, which was illustrated by Ryoichi Ikegami, was adapted into a 1995 live-action film by French director Christophe Gans.

Goseki Kojima was a Japanese manga artist known for his collaborations with Kazuo Koike. The team was often referred to as the “Golden Duo.” Kojima’s best-known work was Lone Wolf and Cub. Other titles attributed to Kojima are Samurai Executioner and Path of the Assassin. In 2004, Kojima won an Eisner Award.