Counterprobe — Carole Nelson Douglas

Little did Dr. Kevin Blake know, when he first encountered the amnesiac Jane Doe, that she was a "probe" sent from an alien world to gather intelligence about humankind. As he began to unlock her memories he discovered two extraordinary facts: that she could kill with her telekinetic powers; and that he was in love with her, with the human soul beneath her terrible secrets.

Now the two of them are on the run -- for although they thought they had fought Jane's alien masters and won, the aliens have found a sinisterly simple solution for calling their probe home...