Caelius , a high-ranking lord among vampire nobility, undergoes an unexpected transformation while investigating anomalies within their territory. During the crisis, they cross paths with a young werewolf named Rehgar, forming an inextricable bond. Though their races are sworn enemies, the two are forced to embark on a journey together to uncover the truth behind the hidden darkness festering within the vampire realm. Along the way, their connection evolves from a mere contractual relationship into that of inseparable soulmates.