Burning Water by Mercedes Lackey is the first book in her Diana Tregarde series. Tregarde is a witch and a "Guardian" sworn to protect mankind. an old college friend. He's also psychic. When cattle mutilations turn into dead bodies he knows who to call. He has to sell Diana to his boss as an expert in cults.
An Aztec god has returned and he intends to make this world his. In order for him to gain the ultimate power, a series of ritual murders have to be committed. Diana and Mark have to find and stop him before he (and his minions) finish the ritual.
I found the book to be really simplistic. Having finished it, I'm wondering if Lackey had intended to make this a series from the beginning. Burning Water creates the character of Diana quite well. Learning about Diana is the most interesting part of the book.
The first part of the book feels like the reader is thrown into a book already in progress. We slowly get information about who these characters are and what lead them to this point. That part of the book is well done.
The rest of the book is one cliche after another. At least they're cliches today. Maybe back in 1989 when the book was published they weren't. I don't remember. All I know is that the plot had no surprises. Everything was telegraphed so even the most inattentive reader would not get lost.
I just didn't care whether or not Diana figured out what was going on or how to stop it. I knew that there were 2 other books in the series (so far... there are rumors of a fourth book in the works) so I knew she didn't die. So maybe knowing that "good" would triumph over "evil" made the book less interesting.
Now that I think about it, having Diana fail and then have the series be about how she stays alive to continue to fight against a god might make it really interesting. As things stand, I doubt I'll bother with the rest of the books in the series.