Monster hunter Wyatt disappears after infiltrating the Black Tower Research Institute, only to awaken in the experimental zone as D-13, a monstrous test subject. With his memories gone, he must hunt other specimens and devour their cores to survive. As his body evolves, he begins to remember why he came here. His teammate Elena recognizes D-13 as the missing Wyatt. Together, they uncover a horrifying truth: the monsters hunters have been sent to eliminate were once human, transformed by the Black Tower. Deep within the facility, Dr. Valen has gathered the cores needed to resurrect an ancient god but lacks a vessel capable of containing them. Yet D-13, a specimen meant to be destroyed, survives every core he devours.