Dead Heat — Patricia Briggs

The Alpha and Omega novels transport readers into the realm of the werewolf, where Charles Cornick and Anna Latham embody opposite sides of the shifter personality. Now, a pleasure trip drops the couple into the middle of some bad supernatural business…

For once, mated werewolves Charles and Anna are not traveling because of Charles's role as his father's enforcer. This time, their trip to Arizona is purely personal--or at least it starts out that way...

Charles and Anna soon discover that a dangerous Fae being is on the loose, replacing human children with simulacrums. The Fae's cold war with humanity is about to heat up -- and Charles and Anna are in the cross fire.