Angel Machidiel and demon Alastor have been denying the attraction they feel for each other for centuries because relationships between angels and demons are forbidden.

Things change forever when they both fall for the same mortal man and begin a relationship with him. Together with Tristan, the ménage they form is filled with jealousy and insecurities, passion and love.

Only time will tell if the relationship they have forged together is made in Heaven or Hell.