Lucifer Morningstar. THE INFERNAL CROWN SERIES, #1

Lucifer Morningstar: Book One begins at midnight on a street corner, when a woman who has spent her entire life solving other people's impossible problems comes face to face with the one thing she cannot file, categorize, or manage away. Angela Williams is twenty-six years old, a nursing student, and the unofficial adult of a family she did not choose. When her stepfather Harold borrows fifty thousand dollars from the wrong man, Thomas Moore, a criminal with thirty years of power and patience, Angela becomes the collateral.
Thomas does not want his money back. He wants a wife. He wants an heir. He wants a transaction. Angela says no. Then she walks into her church at five o'clock on a Thursday and finds a man sitting in her grandmother's pew. He gives his name as Lucifer. He has been following a signal through the space between worlds for forty-seven nights. He is wearing borrowed clothes and carrying ninth-century gold coins and does not know how bus cords work.
He is also, she will come to understand, the most honest thing she has ever encountered: a ten-thousand-year-old sovereign of the underworld who has decided that this specific woman in this specific church on this specific Thursday is the reason he crossed into the mortal world at all. What follows is not a rescue story. Angela does not need rescuing. What follows is something older and more complicated: a woman who has never been able to rely on anyone learning what it means to be the person someone else has been looking for across ten millennia.
Lucifer Morningstar is a dark paranormal romance about permission and power, about the specific courage of asking for what you need, about a man who spent ten thousand years governing the dead and is defeated, completely and without defense, by a woman who reorganizes his honey by flavor profile. It is also, in its final chapters, the beginning of something considerably larger than a love story.