This 35mm screening is presented by Josh Saco of Cigarette Burns Cinema. More details here.
Here is the Regent Street Cinema introduction:
On 20th December, physicist Lionel Barrett takes a small group of psychics to get to the bottom of the strange stories in Belasco House, a notoriously haunted house. The Legend of Hell House is a titan of haunted house films, steeped in atmosphere with an outrageous performance from Roddy McDowell, they don’t get any better than this. We’ll be joined by director John Hough for a discussion and Q&A after the film.
Here (and above) is the trailer.