Ready Or Not by Sheridan Anne

Her mind birthed the monster, but his wicked obsession set it free.

Just when forensic pathologist, Harper-Rayn, thought she had put her horrifying stalker behind her, a new threat is born from the depths of her trauma. More sinister and calculated than ever before.
This new stalker is as real as they come. Emerging not as a hallucination, but as a living nightmare, one that’s been waiting for her longer than she could have ever known, watching from the shadows and anticipating his chance to strike.
The masked terror brings Harper’s past to life, twisting her mind with fear and unease. He manipulates her every move and as he watches her unravel, he leaves just enough doubt to question her own sanity. Is she going crazy? Losing her mind? And after everything she’s already suffered through, who’s going to believe her now?
No one… except the one man she should never want.
Her forbidden lover, her delicious step-uncle, Knight Slater.
Determined to unravel this twisted web of secrets, obsession, and betrayal, and put an end to Harper’s suffering once and for all, Knight must face the impossible—even if it means sacrificing himself to protect the one woman he’s ever loved—the one woman he should never have touched.
As the masked figure closes in, Harper will risk it all—not just her career and reputation, but a love that defies every boundary, to stop a madman who’s determined to finish what her nightmares started.
Ready or not, he’s coming for you.