Whilst on the way to visit the town where Henry James lived, a chance encounter with a spiritualist on a train sends the Doctor and Romana on the trail of a ghost. It's the most convincing case of haunting he's ever heard of, he tells them. And so, on their arrival, does it appear to be.
Things go bump in the night at Malkin Place. The voice of a crying child. Birds bursting into flight. Strange movements in a seance.
The Doctor is determined there must be a rational explanation. But is science always the answer to everything?