The Rescue (The Medusa Project Book 3) by Sophie McKenzie

Until recently, the Medusa teens lived under the protection of William's brother, Fergus Fox, at his North London boarding school - Fox Academy. However their existence has now became known to members of the criminal underworld, so they are being taken to a secluded training camp in Spain, where their identities can be kept secret. Now Dylan has been kidnapped, and this time only Ed can help set her free...

It was really good. I didn't want it to end. G.S. (S2) *****