I read and really enjoyed A Class Apart, and What Happened in Witches Wood is on my soon to be read pile.
Here's the synopsis for book one, to whet your appetite.
Teenage twins James and Samantha Blake are caught up in a seemingly random terrorist bombing while on a school trip. Many of their friends are killed. When the twins wake up in hospital, their lives have changed forever.
The doctors are amazed at the speed with which James and Sam recover from their injuries and, when the twins begin to exhibit extraordinary powers, it is obvious that something incredible has happened.
As James and Sam attempt to overcome their fears and embrace their new abilities, a series of murders and disappearances start plaguing the hospital. The twins aren't the only ones with special abilities and it becomes apparent that someone is coming for them.
Will James and Sam be able to survive the nightmare into which they have been plunged? Who, or what, is behind the murders at the hospital? And was that terrorist incident quite so random after all?