On a distant planet Donna gets her palms read.  While there a bug creature climbs on her back.  The woman causes her to think about the day she met the Doctor and how things would have been different if she'd just turned right instead of left.  Donna begins to live in a very different England where there was no Doctor to save them from horrible disasters.  During these events she continues to meet a mysterious blonde-haired woman.  She eventually consents to meet with her and UNIT and they send her back in time in order to get herself to turn left.  She must sacrifice herself in order to do so and as she's laying there, the woman whispers two word into her ear.  Later, back on the alien planet, Donna tells the Doctor about her "dream" and tells him the two words - "Bad Wolf".