Ghost

Murder sits at the center of the plot — Killian killed Ellie's father and works as a professional killer ("deleter") for a secret organization — and reviewers repeatedly flag the violence, torture, and gore as intense and "graphically descriptive." Ellie goes through a period of captivity/imprisonment and what several reviewers describe as genuinely traumatic, kidnapping-adjacent harm at the hands of the antagonist group, leaving her with lasting PTSD and identity/memory struggles during recovery. Killian's backstory involves years of covert stalking and surveillance of Ellie before the story even starts, plus heavy manipulation, gaslighting, and psychological-manipulation/brainwashing tied to the secret society ("the Order"). Expect pronounced power-dynamic tension (doctor/patient, captor-adjacent living arrangement) and a relationship multiple reviewers describe as sitting right on the line between toxic and addictive, with Stockholm-syndrome-adjacent undertones as Ellie's feelings develop for the man connected to her father's death. It's graphic in places ("wincing," "gritted teeth," "not for the faint hearted") but ultimately resolves with healing, found family, and an HEA.