Un experimentado asesino está haciendo su último trabajo para la organización antes de retirarse, pero la compañía de una novata y una situación inesperada cambiarán sus planes de forma radical.

Nuestro asesino habla con la diosa que le ofrece la reencarnación y le dicta las condiciones, aunque la misión será complicada: asesinar al excepcional héroe con las habilidades de una persona normal. Pero eso no evita que comience su nueva vida en un nuevo mundo con un claro objetivo.

Lugh comienza a practicar magia con Dia, su nueva tutora, y empieza a descubrir cómo funciona la creación de nuevos hechizos.

Lugh rescata a una jovencita del ataque de unos lobos en el bosque y decide acogerla y entrenarla para que sea su ayudante en su trabajo.

Lugh se enfrenta a una última prueba por parte de su padre: debe enfrentarlo en combate. Lo importante no es vencer, sino que Lugh demuestre el nivel de sus cualidades como asesino de los Tuatha Dé.

Mientras Lugh se prepara para asumir la identidad que ostentará por dos años, en la ciudad de Milteu unas niñas se ganan la vida en las calles de forma honesta y sueñan con el futuro hasta que un grupo de tratantes de personas las secuestra para usarlas de modos viles.

Lugh comienza su nueva vida como Illig, hijo del comerciante Balor, donde no tarda en ganarse su confianza y preparar un nuevo producto que amplíe la compañía de su nuevo falso padre. Esto hace que pronto otros comerciantes lo pongan en su punto de mira.

With the success of his cosmetics brand Orna, by acquiring financial power and the Balor Trading Company's information network, Lugh has gained even greater strength as an assassin. However, since being reincarnated in this world, Lugh still has not completed a proper assassination. Then, Lugh's father Cian tells him that he doesn't have to become an assassin--

Lugh receives a request for assassination. He takes Talt with him and goes to a commercial city, Pisaal. He decides to gather information beforehand to justify whether the target needs to be assassinated. Once there, Lugh saw the suffering of the people that was caused by his target. It's a tragic sight as a young child is forced to sell drugs while her mother was emaciated and was also addicted to it. Thus, Lugh formulates an assassination plan based on the information that Maha had collected. He was successful in killing for the first time in this life, though he soon felt the weight of his action and became emotional after witnessing the wife of the target grieving.

In front of Lugh and Talt who've just finished a magical training camp in a deserted island, Maha appeared with information. It's about Swoigel kingdom being engulfed in a civil war. Lugh heads toward Dia, but Viecone territory seemed peaceful as always. Lugh was still worried, but Dia ignored him and suggested to go on a date instead.

Lugh got a assasination request for Dia. And the principal is Count Viecone, who is Dia's father and Cian's old friend. Cian expects Lugh can finish the assasination. But if he refuses it, Cian will do it with his own hands.

Lugh and Dia's father come up with a plan to fake Dia's death and safely sneak her into to the Tuatha Dé region. Unfortunately, the arrival of Setanta MacNess thwarts the plan before they can enact it. As Setanta is the wielder of Gae Bolg, Lugh knows that he will not survive a direct confrontation with him, so he fires a magnetically propelled tungsten projectile into the atmosphere and stalls Setanta long enough for it to obliterate him. Afterwards, the Tuatha Dé family adopts Dia under the guise of being Lugh's younger sister, completing the mission. Sometime later, Lugh receives word that the Hero, Lord Epona Rhiannon, has arrived in the Alvan Kingdom.