The Great and Terrible by Gena Showalter

When twenty-year-old college dropout Moriah Shaker runs into an empty chapel to escape an unexpected storm, she’s catapulted into another world Wizard of Oz style. Unfortunately, she winds up in the treacherous realm of Hakeldama, a fantastical but brutal land where justice is twisted and innocents pay for crimes committed by the elites—and she’s now marked for death.
On the run and determined to get home, Moriah heads for the City of Lux, where a rumored portal between worlds exists. At her side are the most unlikely of companions. A scrappy hustler, a cranky ex-mayor, and a growing beast-dog. But the one who fascinates her most is Jasher, a heartless executioner who hides a terrible secret. Together, they’ll battle bounty hunters, lethal poppies, and winged monsters. Though Moriah doesn’t yet know it, there’s nothing more dangerous than their forbidden attraction.