"Doctor Who and the Zombies" has so much potential, doesn't it? And indeed, that's what you get in this book.
"Doctor Who and the Cthulhu Cult" has tons of potential as well. We get that too.
Thank goodness that once again, we have the real Doctor here! Also, thank goodness, this book is better than Lucifer Rising. The TARDIS crew characterization is strong, as is the plot. The engine of this book rumbles along smoothly if sometimes a bit loudly. Bad guys? We have them aplenty. Best of all, the actual religion of voudoun is left unmaligned.
For a pagan like me, this is crucial. I know enough about the zombie mythos to recognize that the process of creating a zombi has been shown to be a bit different by more recent research, and I can live with that. What would have brought me screaming out of the story would have been uniformly evil followers of the loas, and we were spared this.
That's not to say there aren't racially problematic points to this book. There certainly are, starting with the fact that with one exception all of the good guys are white or mixed-race. But as I said before, there are bad guys aplenty, and we get lots of those with white skin. We are not left having to deal with black equals bad and white equals good, which also would have brought me right out of the story.
I could have wished for more subtlety here and there. I figured out one of the identity issues early on, and "Doctor Howard Phillips" screamed out in a book which had already mentioned the Great Old Ones by name.
I'll forgive it all, though, for the moments of clarity experienced by Ace. I'll forgive it for Benny being genre-aware and realizing what's going on, for her determination not to be a screaming female, for her wry sense of humor. I'll forgive it for the Doctor explaining that the Great Old Ones will act a certain way and being right, despite all hints to the contrary and for his not-at-all quiet rage at the way the people of the island are treated.
Does it have weak points? Sure it does. This is the strongest outing since Transit, though, and I really enjoyed it.