This is an example of a movie where some judicious editing would have helped immeasurably.
The first half is an interesting whodunit in which Tomas, a Bohemian detective (well played by Martin Dejdar), attempts to determine the true story behind the death of a servant in the Ravenscroft mansion. His interaction with the mistress of the house, her daughter and governess, and the servants is amusingly prickly for about an hour. Unfortunately, impatience begins to set in when this same cat and mouse, back and forth continues on for another 40 minutes with all parties lying for their own reasons. To make matters worse, the scriptwriter has the inspector become increasingly drunk, an unnecessary plot turn that derails the darkly humorous yet serious tone set in the first half of the film and which struck me as being distinctly out of character for Tomas. Ultimately, the resolution is not interesting enough to warrant the time and effort spent reaching it.
There are good performances from the whole cast, though top billed O'Toole is in the film very briefly in flashbacks as the deceased patriarch. The set design and camera work are wonderful, top honors to art direction. Unfortunately, these positives are counterbalanced by an overlong tale muddled by useless plot contrivances. 2 1/2 stars