Not a good series
All in all, this is not a good series. I remember liking it quite a bit as a child. In fact, I still think Sleepwalker looks pretty cool, and could have been a better book. But reading it now as an adult... this is a d-list product of the 90s. If you're into it, the good news is you should be able to pick up the whole series for cheap, cuz no one cares about it anymore.