Can You Hear Me?

What connects the nightmares of a young girl from 1380 Aleppo to strange happenings in the present day? Who is the shadowy figure who appears in the night? And what have they got to do with a young woman in the far future, trapped in an impossible prison? Time catches up with the Doctor's friends, whose wants and dreams are set on colliding. They must now embark on a mission that will draw out their innermost fears, to be confronted.