- You may be looking for the audio story The Witch from the Well.
At one point, she accidentally landed, and got trapped, in a pocket universe with the Crooked Man. While she was only there for around 5 minutes from her perspective, her presence in Normal Space was felt from the beginning to the end of the planet Earth.
In the 17th century, a local clergyman saw her, and wrote that her presence was accompanied by knocking that he compared to the Devil himself. During World War II, American airmen stationed at the House left "offerings of tin Spam." The tins were found in 1965, bricked up in the servants pantry, along with "a number of hand written notes, appeals, to the ghast; 'for the love of god, stop screaming.' "
She was called 'the Witch of the Well', as a reality well was found on the property of the Caliburn House.
Hila was finally saved when the Eleventh Doctor, through the power of Emma Grayling, entered the pocket universe to retrieve her. She crossed through a wormhole and arrived at the Caliburn House in 1974. Her ultimate fate is unclear; according to the Doctor, her status as a pioneer explorer of time makes her a fixed point in time, thereby preventing her from being returned to her own time, however he soon revealed to her that Emma and Alec were her ancestors. (TV: Hide)