As a Virtue to the High Throne, Cassie's main function is concocting serum to be applied by those angels deployed on Earth missions. Thus, when she receives her very first actual field assignment from the Almighty, she is beside herself with excitement. The Almighty has never once sent a Virtue beyond the Pearly Gates, preferring to instead keep their existence under wraps. Yet for whatever reason, Cassie is the exception, and she is determined to prove herself worthy.
Cassie is so excited, in fact, her elation initially overshadows the shadier aspects of her assignment. For starters, her target is preacher-turned-politician Grayson Bailey, and Big J wants Cassie to seduce him before the preacher falls prey to the competition, who just happens to be Luxi, the Sin of Lust. This wouldn't be a problem were Cassie any other Virtue, but she's not. She's the Virtue of Chastity and charged with preserving and defending the art of abstinence from the sinful lusts of man. She wears a chastity belt at all times, even while in Paradise, to ensure her purity is not compromised.
Once she realizes the nature of her assignment--that success in the field means expulsion from Paradise--Cassie finds herself lost in her very own crisis of faith, and very close to understanding what it means to be damned if you do and damned if you don't.