Into the Dark — Lyneal Jenkins

INTO THE DARK is the seventh book in the Phoenix Rising series, which follows Ana as she is drawn into the secret world of the Siis, an ancient race of empathic beings torn apart by war, treachery, and the consequences of past actions.A psychotic Siis has direct access to Ana's mind and can track her at any time, a Siis who intends to destroy humanity. Ana needs a plan that will stop him while keeping her sanity in check. But, as old enemies return, Ana soon realises that her sanity is the least of her worries. She will soon suffer her greatest regret yet.