Moya, a Celt in Roman-occupied Britain circa 125 AD, was married to Colin, a warrior leader facing overwhelming Roman forces under Marcus Octavius. To prevent bloodshed, she drugged Colin and approached Marcus alone, offering her body in exchange for her people's safety. Marcus accepted but immediately betrayed her, ordering the attack. Moya retaliated by stabbing him with a hidden dagger, unaware of his immortality. Marcus survived, captured her, and crucified her as punishment.

Mortally wounded on the cross, Moya witnessed the Roman assault. Colin found her, freed her, and held her as she died. With her last moments, she expressed fear for his life and made him swear an oath not to pursue vengeance against Marcus.

Her death unintentionally ignited Colin's 2,000-year quest for vengeance against Marcus, directly opposing her final wish. Moya's soul perpetually reincarnates, destined to reunite with Colin. She reappeared as Deborah in 11th century Scotland and later as Dahlia, a resistance fighter in post-apocalyptic New York City in 2187. Dahlia unknowingly echoed Moya's ancient words, triggering Colin's recognition through a flashback stare. Despite these encounters across lifetimes, Colin's obsession with revenge blinded him, preventing full recognition or reconnection.

Moya's spiritual presence indirectly influenced Colin. Amergan, a ghostly druid guiding Colin, revealed her cyclical reincarnations and suggested her future return. In the climax, Colin experienced a vision of Moya's spirit calling from an afterlife realm. This vision, coupled with Dahlia's death, contributed to his spiritual renewal and decision to fight for others instead of personal vengeance.