Angelus, Francesca, and Jacobus have not been home in 2000 years.
Each possesses a flaw which keeps them out of heaven.
Francesca, unsure what her flaw is, makes it her mission to help her friends overcome theirs, whether they want her help or not. Angelus, grieving over a long-ago relationship with a mortal woman, refuses to help women in need. Jacobus prefers to drink and gamble instead of getting to know mortals and their problems. Francesca believes that if they just follow the rules, they will be allowed to return to heaven.
But following the rules carries its own cost.
To complicate matters, Lucifer, the archangel who judges their worthiness to return to heaven, has his own ideas--which may lead to their salvation or utter destruction.