No Way But Down (Revised Edition). A Chicago Dragon Chronicles Novelette (en Inglés) - Ayla Jones

Brianna Jones is a Chicago private investigator who finds missing people for a living. She's practical, skeptical, and very good at her job.
Blind dates? Not so much.
When a charming stranger leads her beneath the city streets, Brianna stumbles into a hidden world she never knew existed: dragon shifters living quietly beneath Chicago.
And they are guarding secrets centuries old.
Among them is Amelia Farehart, the woman Brianna was hired to find eighteen months ago. Amelia is alive... but caught in a community bound by ancient laws and even older fears.
Getting out is only the beginning.
To protect Amelia, and prevent a fragile truce from shattering, Brianna must uncover something the dragon shifters have been searching for since the medieval wars:
Legends of true female dragons.
Her only ally is Jerry Farehart, Amelia's steady, sharp-minded brother. As they follow a trail of folklore and ancient cave paintings from Chicago to the limestone caverns of Montana, Brianna discovers that this case is bigger than a missing-persons file.
It's about trust.
It's about history.
And it may change both their futures.
No Way But Down is a clean paranormal romance filled with hidden worlds, slow-burn chemistry, and light adventure, and the first book in the Chicago Dragon Chronicles.