Sally and Alex (Darby & Hutton) inherit a beautiful, old, Victorian mansion and set about restoring it to its former glory. In the process, she finds a bricked over fireplace in the basement. Mr. Harris, the handyman (William Demarest) tells her to leave it alone, but she jimmies open the coal scuttle, which leads, unexpectedly, to a subterranean room. She closes it back up and goes about her business, unaware that she has freed a group of murderous goblins who are obsessed with taking her back with them into the room. She goes through a series of near misses, as the creatures try to claim her soul, though her pleas for help fall on unconvinced ears - nobody will believe her. Will she defeat the underworld creatures and survive?
This film has become something of a cult classic, inspiring a remake that was released under the same title just this past August. There are interesting sociological undertones to the plot line, with Sally's failure to convince others of her peril representing women's frustration at being unheard in society at the time. You can find this film in the Warner Archive Collection on DVD. A fan-made trailer is above, uploaded to YouTube by brutallodotcom.
Obscurity factor: 3 (available on DVD, considered a cult classic by some)