Jacaranda by Cherie Priest

Priest continues to be an effective crafter of dread and tension, and
while Jacaranda is explicitly a novella, there are a few areas where
the reader might wish for more. Despite being set in her Clockwork
Century universe, aside from a few background touches, this could
easily take place in any version of the Old West, and the book seems
to be building to something bigger than it ultimately winds up being.
The characters here are vivid and interesting enough that hopefully
this particular adventure isn’t the last of we hear of them, or of the
survivors at least.

Just off the coast of Texas, on the island of Galveston, there’s a
hotel named the Jacaranda. It would be the nicest resort in the area,
if not for the fact that everyone who comes there is dying one by one.
Now, a priest with a bloody past, a nun with a bloody secret and an
old Texas Ranger who specializes in the odd and uncanny have all come
to the Jacaranda to put whatever hungers there to rest — or die
trying. — RT Book Reviews, 4 stars