Even though I knew the end

An exiled augur who sold her soul to save her brother's life is offered one last job before serving an eternity in hell. When she turns it down, her client sweetens the pot by offering up the one payment she can't resist-the chance to have a future where she grows old with the woman she loves. To succeed, she is given three days to track down the White City Vampire, Chicago's most notorious serial killer. If she fails, only hell and heartbreak await.