Stream Demented Online Free – Watch Full Movie from Home at 123Movies. . To the outside world, the old boarding house seemed safe and inviting, tucked away on a tree-lined street in a cozy and quiet neighborhood. But appearances can be deceiving. One by one the boarders are about to learn its terrifying secret. A secret they'll carry to their graves. 'Demented' is an exercise in unrelenting, mind-numbing terror. Based on a shocking true story, the film is all the more horrifying because it really happened... maybe in your own town!