Books in the Dark Ones series

Amongst the Dark Ones there is one they call The Betrayer, one who is doomed to hand his own kind over to a demon lord... for eternity. But now a small boy s been kidnapped, and it s up to Nell Harris a Charmer no, literally, that s her job to rescue him. Problem is, she can t help but find The Betrayer a teeny, tiny bit attractive... is it possible he is not as soul-less as he seems, or has her penchant for bad-boys just gone into overdrive?