Like the previous book in this series, this one has a paranormal aspect to it. It’s played off as genetics, with the two women being created in a government lab, but it’s not quite believable.
Grace is even more powerful than her sister, Shea. They can both heal, but Grace can completely heal someone - taking the wound or illness into herself (which can be fatal to her). This makes more people interested in Grace than her sister, since Shea can only temporarily block pain and help the healing process along.
I still find this unbelievable, but I’ve just decided to go with it. I’m really annoyed with the idea of them both having powers. Aside from these two women this series is completely modern with nothing about magic or powers of any sort. I’d actually be less annoyed if more people in the series (like Rachel or one of the Kelly brothers) had powers. I get that Shea and Grace have these powers because of government interference, but it really annoys me!