Letters in Blood (en Inglés) - Vada Cross

She wrote to a stranger behind bars. He memorized every word.

Fallon Reed is drowning in silence. A lonely botanical archivist in Boston, she spends her days preserving dead flowers and her nights writing anonymous letters to Inmate 704 - a convicted felon she will never meet. He is her only confidant. Her darkest confessions pour onto the page: her isolation, her fears, the hand she presses against her bedroom wall at night, imagining someone pressing back.

She doesn't know he's already out.

Gideon Thorne served eight years for a crime of calculated violence. Fallon's letters were the only thing that kept the monster in him quiet. Upon his release, he does what any obsessive, patient predator would do - he finds her. He moves into the apartment across the hall. He introduces himself as Gabriel, a charming architect with a warm smile and a talent for making broken things feel whole.

Gabriel doesn't exist. Every kind word, every shared coffee, every touch is reverse-engineered from her own letters. He knows her favorite drink, her deepest fears, her most desperate fantasies - because she mailed them to him, one confession at a time.

As Fallon falls for the perfect man next door, she's torn apart by guilt - because she's also falling for the dangerous inmate she writes to in the dark. She doesn't know they're the same person. She doesn't know that every wall she presses her hand against has him standing on the other side.

By the time she discovers the truth, his ink is already in her veins.