Cellar Door by Trisha Wolfe

To hunt a killer, I search the darkest corners of Seattle. As a private investigator, I comb through the seediest organizations to locate my prey.
There’s a monster roaming the streets, and his blue, stone-cold eyes are all I see when I close mine. That he lives haunts my waking hours. Through the storm, I watched him murder a man. I saw his evil. And when the moment strikes to exact my revenge, he steals the only witness to his crime.
Me.
In his cellar, I unravel every dark and twisted secret; the sordid mystery that entangles both our lives. When the storm passes, and the dark chamber has heard our confessions, which one of us will survive the truth?