Folie à Deux by Cynthia A. Rodriguez

Be careful with that one.
These are the first words of advice given to Abel Sommerfeldt upon entering Silverwing Mental Institution. He has no idea what awaits him here, in a place where hope goes to die, and demons run rampant.
Certainly not a disarmingly beautiful young woman with violent tendencies and an itch for defiance.
She’ll paint the walls red with your blood.
But Abel was never one to listen. Not even to his dead mother, whom he still hears, whispering warnings about the girl named Rose with white blonde hair who feels like fate.
Basherte.
He quickly discovers just how dangerous freedom is for Rosamunde Montgomery.
Because sometimes, the most beautiful roses are riddled with thorns.
And he’s willing to learn the hard way.