A half-mortal, half-god warrior known only as B has wandered the world for over 80,000 years, cursed with an uncontrollable compulsion toward extreme violence and the inability to die. In the present day, he works as an extraordinarily effective weapon for the United States government, undertaking black-ops missions that are too dangerous and violent for any normal soldier. In exchange, the government promises to help him unlock the secrets of his mysterious origin and, ultimately, grant him the one thing he truly desires: the end of his immortal life.

B, sometimes referred to as Berzerker or by his birth name Unute, which means tool or weapon, possesses godlike regenerative abilities, superhuman strength and speed, and a perfect memory that forces him to carry the psychological scars of every act of carnage across the centuries. Between brutal missions, he is studied and counseled by Dr. Diana Ahuja, a government scientist assigned to unravel both his biology and his mind. Through their therapy sessions, a strong connection develops, and B begins to recount his repressed memories. He was born in prehistoric times to a human mother who prayed to a cosmic entity for a weapon to protect her nomadic tribe from surrounding oppressors. The entity answered by impregnating her, creating a living weapon of monstrous rage. B spent only two months in the womb, grew at an accelerated rate, and was raised by a surrogate father who trained him as a tool for slaughter. His surrogate father’s greed for conquest eventually led to the tragic death of B's mother and the destruction of their entire tribe.

Following this loss, B wandered the Earth alone, fighting in countless wars, toppling empires, and inadvertently inspiring a cult-like following of people who revered him and sought, for centuries, to replicate his abilities. The weight of his curse grew heavier as loved ones aged and died while he remained unchanged, strengthening his desire to finally die. In the present, a high-ranking U.S. official named Caldwell, who is secretly a member of this ancient cult, oversees the government's attempts to use B as a living weapon while trying to replicate his DNA to build immortal super-soldiers. B remains indifferent to their intentions as long as they pursue a way to make him mortal. Together with Dr. Ahuja, he confronts his repressed emotions about his mother's death and uses a special device to connect with the cosmic entity that is his father. This connection reveals the location of an artifact capable of permanently removing his abilities and granting him mortality.

The climax sees B, Diana, Caldwell, and the U.S. military traveling to retrieve the artifact. Caldwell's machinations come to light as he orchestrates the transfer of B's abilities to himself, gaining the uncontrollable urge to kill. Now mortal but no longer burdened with immortality, B must confront Caldwell in a decisive battle, with Diana using her own newly developed psychic powers, awakened through her connection to B and the cosmic entity, to help overcome the threat. The story explores themes of violence, memory, and the desperate search for an end to suffering across a brutal and blood-soaked existence that spans all of human history.