(But let me throw in the standard disclaimer first: publishers sent these two books to me, but I haven't read them as of this moment, so what I am about to tell you might not be, strictly speaking, as accurate as it might possibly be. It's all true as far as I know, though.)
The Isis Collar is the fourth book in the urban fantasy series "Blood Singer" -- which began with Blood Song, sensibly -- and the first not to have the word "Song" in the title, so fans of the series be warned. It's by Cat Adams, which is the open pseudonym of C.T. Adams and Cathy Clamp (if I were Clamp, I'd be mildly peeved that my joint pseudonym was practically my collaborator's real name, but they've been working together for many years, and I suppose they're entirely happy with their relationship), who also wrote the bestselling Sazi series. (Not to be confused with the Scalzi series, which is a secret SFWA protocol for total world domination...but I've already said too much.) Anyway, the heroine of this series has the usual markers for an urban-fantasy uber-woman, as the first line of the back cover makes clear:
Celia Graves juggles vampire abilities and the powers of a Siren -- not to mention her complicated relationships with two powerful mages and her dysfunctional family -- while battling evils large and small.Makes me tired just reading about it. Isis Collar is a trade paperback from Tor, which you will find for sale in the usual places on March 13th (if not earlier).
The Moon Moth is a little more than a hundred pages long, with gorgeous gemlike colors by Hilary Sycamore. I hope I don't have to explain Jack Vance -- though the excellent New York Times Sunday Magazine article about Vance, by Carlo Rotella, is here reprinted as a foreword -- or "The Moon Moth," one of his great burst of 1960s stories (which also included the Hugo-winners "The Last Castle" and "The Dragon Masters"). The Moon Moth is published by First Second.