Treason — Ann B. Harrison

In the third installement of this young adult series, Nera has found her place and so has Sully. But with their best friend Brie acting weird, Nera must ask Bones for help. This is something she can't cope with on her own and none of them expect what they discover. It is the bond that finally brings the two of them together much to Sully's horror. He wanted to keep Nera to himself and he isn't pleased that Bones has laid claim to her heart.
But at the end of all this, will any of that matter if what Brie is doing pulls them all apart?
An unmissable ending you won't see coming.