Kelley Armstrong's thirteenth and more-or-less final book in the Otherworld (formerly Women of the Otherworld) series is named, with admirable simplicity, Thirteen. It completes the sub-trilogy begun in Waking the Witch and Spellbound, with the main narrator again being the young witch/sorcerer/demon hybrid Savannah Levine. As before, I refuse to even attempt to summarize Savannah's backstory. Read the novels.
I have to give Armstrong some serious props for actually ending her series before it jumps the shark and for doing it with a pretty creditable bang. I won't say that every previous character shows up at some point, but she tags all the major ones at least briefly, with many of them narrating a chapter or two, and in general she ties up all the loose ends and everyone lives more-or-less happily ever after or dies very messily, as the case may be.
The general story is that a group of supernaturals led by someone who may or may not be the historical mass-murderer Gilles de Rais are working on an immortality serum using a mixture of vampire, zombie, and werewolf essence. This can also supposedly be used to give supernatural powers to ordinary humans. Unfortunately, the formula has a few bugs in it, and Savannah's sorcerer half-brother Bryce is infected and dying from it. But the Supernatural Liberation Movement sees the bestowing of supernatural powers on humans as a way to enable supernaturals to come out of the closet, a superficially appealing idea which likewise has a few bugs in it. So our heroes are attempting to prevent the infection of more humans and supernaturals with a defective virus, defeat the idea of supernaturals going public, and track down Gilles de Rais before he can proceed to even more dangerous pastimes, like summoning Lucifer. An anti-public-supernaturals group is trying to undermine the whole going-public idea by creating nasty supernatural incidents that are stretching the ability of the non-public supernaturals to cover up. The demonic and celestial realms, which normally do not interfere directly on earth, are feuding internally over the idea of public supernaturals, and all the usual rules seem to have been thrown out: angels and demons are manifesting physically on Earth and lord demons are actually interfering in human events. So it's getting pretty crazy out there.
Fighting the chaos are the morally ambiguous sorcerers' Cabals, led by the Cortez Cabal, in alliance with the werewolf Pack and the Interracial Council. That means we get to check in with the whole Otherworld cast: werewolves Clay, Elena, and Jeremy; half-demon Hope and her werewolf mate Karl; necromancer Jaime; vampires Cassandra and Aaron; Cabal heir Sean Nast (Savannah's other half-brother);angelic half-demon/witch bounty-hunter Eve Levine and her ghostly sorcerer lover Kristof Nast (Savannah's parents); and the sorcerer/witch couple Lucas Cortez and Paige Winterbourne. I suspect this kitchen-sink approach would be overwhelming to anyone starting with this book. I sincerely hope that no one will be dumb enough to do that.
As a series wrap, Thirteen is quite serviceable, if a bit short on the tragedy that feels like it ought to occur in a grand finale. I didn't love it as much as my favorites in the series, and it was a little hard to keep track of everything going on, but I did find it satisfying overall. Other than the "cast of thousands" issue, my only major reservation is Armstrong's general reluctance to bump off significant good guys. It's not that I'm eager to see my favorite characters dead, but I think she passes up some opportunities for strong emotional punches and loses a little realism thereby. The minor characters get mowed down in droves, however.
And Armstrong is already hedging her bets a little as far as the whole "end of series" thing goes. There's a short story at the end that takes us back to where the series started, with Elena and Clay and the werewolf Pack. And there is a promise of anthologies of short fiction to come in future years, and maybe someday a novel again...
In the meantime, I recommend Thirteen, but only after books one through twelve. Shop for yourself: