An incredible, magical thrill ride. So much to love about this book. Bravo to Laurel Anne Hill for writing a masterpiece.

Plague of Flies tells the of a revolt in Alta, California. The story is more fantasy than I had expected. I really did not expect to be about actual ghosts in this story. Catalina is a strong character. She is very fierce and patriotic. I thought the romance was a bit undeveloped. The story is fast-paced but felt rushed at times. Still, I recommend this for fans of Yakimali’s Gift!

This was actually my spooky season read, set in Alta California in 1846 as the Yankees attempt to wrest control of the territory away from the Mexican and indigenous inhabitants. Add in some magical realism, a mysterious and sometimes threatening Spirit Man and his flying horse, and you've got all the ingredients for a thrilling adventure.
I liked the indigenous representation - our heroine is half Costanoan - and while horses did not feature hugely, the equine details were well done.
The magical realism aspect fell a bit short for me, which is probably a personal issue - I like my fantasy worlds to have clear rules and this one was quite vague. If you are looking for a fierce and determined heroine, however, this delivers in spades.

In this thrilling adventure through a little known part of history, you’ll find yourself holding your breath until the very last page, then you’ll find yourself tearing up. Catalina is a daring woman, doing what many others would never dream of, but she stays true to herself, and that’s what matters.

In 1846 Alta California, Catalina Delgado daydreams about her future, as any other young woman would: roping cattle, marrying Angelo Ortega and raising children. But now, invaders from the United States—the Bear Flaggers—have declared war against Mexico, her country. Bear Flaggers have imprisoned one close friend of her family and murdered others. What fate might befall her parents, grandfather and younger brothers? And what about her best friend, a Costanoan servant girl? How can Catalina, only sixteen, help protect all those she loves?

An old vaquero, or cowboy, once predicted a mysterious Spirit Man would someday ride off with Catalina. This has clouded her reputation as a chaste young woman, one reason why Angelo's father doesn't want her for a future daughter-in-law. Now Catalina learns another reason. Her mamá is not her natural mother. Catalina is a mestiza, the daughter of her papi and a former servant woman. Is all she’s ever known a lie?

Catalina prays for guidance, then dares to leave her bedroom at night to seek a spiritual vision, as her grandfather often does. She ends up riding into the sky with Spirit Man, a decision that puts her in the middle of a dangerous game. They remove gold nuggets from a river to prevent Bear Flaggers or anyone else from discovering the treasure. Will this be Catalina's duty for the rest of her life? And despite the situation, she finds herself asking, is Spirit Man good or evil?

For the sake of all she holds dear, Catalina risks what is left of her reputation, her future with Angelo, her life and her very soul. When hopes and dreams clash with cold reality, Catalina finds the fortitude to accomplish what only she can do. A Yankee soldier, the Spirit Man’s horse, and her love might be the only people who can help her as the very thing she wants to do is pulled out from under her.

Overall this book was amazing. Thank you to NetGalley and the publisher for allowing me to read this book in advance in exchange for an honest review.