Well, I haven't finished it, but so far, it's just standard paranormal romance. This is not Dark Erotica!! Yeah, she's abducted, but doesn't really mind, since it's for a good cause, etc. I read edgier stuff from Christine Feehan in Memory Game than here. Now if the heroine gets the "full centaur" treatment later on, that could be interesting, but halfway thru- still hadn't got to it.
Spoilers
This book- I just decided to give up. It's got the kind of sex scenes you'd see in Harlequin Romance Blase or temptation. nothing to write home about. And I was annoyed with it's most unrealistic feature- she just up and leaves her life as a vet- a veterinarian where people depend onher, and she has school loans to pay, and her sister has always leaned on her and she just throws it all away to be, basically, a stay-at-home mom to a sickly baby centaur and love toy for two guys. She just seemed to be a woman of bigger desires at the start of the book. Waste of my money, dudes and dudettes.