After a quick visit to London, the Doctor and his companion Clara meets a young woman who bears witness to an alien abduction. In order to learn more The Doctor invites the woman into the T.A.R.D.I.S but learns that the young Sabrina Noeland might hold a deeper secret that does not just connect her to the aliens but the Time Lords themselves.

Automatically she moved away from him, a tidal wave of guild almost drowned her and it suddenly fell so wrong nearing him and the invisible wall the couple have had created the day she 'died' was now building up just as fast as they had broken it down.