Angel Machidiel and demon Alastor have been working against each other for centuries. Each human Alastor seeks to corrupt Machidiel makes it his mission to save. For as long as they have been rivals they have been denying the attraction they feel for each other because relationships between angels and demons are forbidden.
For Alastor, rules are made to be broken and when he and Machidiel set their sights on the same mortal man it is only a matter of time before Machidiel is breaking some rules of his own.
Together with Tristan, the human they are both falling for, they form a ménage filled with jealousy and insecurities, passion and love.
It might be a sin for an angel, a demon, and a human to live and love together, but for the three of them it is heavenly.