I am The Doctor & I am afraid
The Doctor is trapped in a pocket universe, while Clara struggles with an out of control TARDIS. Psychic Emma Grayling, attempts to open a gateway for the Doctor to return but he knows if he escapes so to could a terrifying creature.
The only mystery worth solving
The Doctor hopes empathic psychic Emma Grayling may be able to shed some light on Clara's unique existence, the Doctor goes to 1974, where Emma and her future husband Prof. Alec Palmer are investigating a ghost known as the Witch of the Well, in Caliburn mansion. The Doctor borrows Alec's camera and uses the TARDIS to take pictures of the mansion's location throughout time. The journey is too much for Clara as she graples with the nature of her existence. As the Doctor puts it; "You are the only mystery worth solving."