Even Although I Knew the Finish by C. L. Polk
What would you do for these you’re keen on? The unnamed magical detective on this great novella would do something, which is how she ended up promoting her soul to the Satan to avoid wasting her brother’s life. (At all times with the souls. Doesn’t the Satan ever need the rest, like a pleasant M.L.T., a mutton, lettuce, and tomato sandwich when the mutton is sweet and lean and the tomato is ripe?) Now, along with her destiny in Devil’s fingers, the detective resides on borrowed time, and he or she’s okay with that, till she falls in love. So she needs to renegotiate the phrases of her contract, and the Satan agrees to make her a deal involving a case: discover the Chicago serial killer, the White Metropolis Vampire, in three days, and she will keep and reside a contented life of affection. Fail, and it’s pitchforks and hellfire endlessly.