(Some Spoilers) Murder and madness is mixed in with a little of the supernatural in "House of Secrets" and the ending, even though it wouldn't knock you off your feet,has a nice and surprising twist to it.
Inheriting her parents Southern Plantation Marion Lambert Ravinel, Malissa Gilbert, can't keep up with the daily grind of the place that's been converted into a sanatorium by her late father Mr. Lambert. Having a bad heart Marion let's her husband Dr. Frank Ravinel, Bruce Boxleitner, run the place but he's running it into the ground. He's Secretly having the Mansion turned into a casino behind Marion's back has his frail and sensitive wife throw a fit when she finds out about it.
Marion is also very angry at her husbands attempt to throw the maid Evangelin,Cicely Tyson, out of the place because of her knowing what the doctor is up to and working with her knowledge of the black arts and Voodoo to put a hex on him. This in order to stop Ravinel from destroying the Plantation which she and her parents and great-parents worked at all their lives, and which is the only home that she knows.
Working at the sanatorium is nurse Laura Morrell,Kate Vernon,who Dr. Ravinel got out of prison for the murder of a man who tried to rape her some eight years ago. With Laura having to have a job in order not to break her parole she's more or less being blackmailed by the good doctor to stay at his medical facility, even though she just about had it with the abuse she's taking from him. With Dr. Ravinel about to sell out his medical profession to become a part-owner of a casino and throwing everyone in the sanatorium out in the cold Laura, together with Marion, concocts this plane to murder Dr. Ravinel and make it look like it was an accident.
Getting Dr. Ravinel to come over to Bayou Country during "Fat Tuesday" week to pull this "perfact crime" off the doctor almost blows the entire plan when he tell Marion, as she gave him a glass of drug laced lemonade, how much he loves her. Marion moved by his sudden show of affection for her then purposely knocks the glass out of his hand to keep him from drinking it. Back to "normal" now Ravinel, mad at her spilling the lemonade on his clean suit, becomes more like his old self again by smacking Marion across the face so hard that he knocks her to the the ground and almost out cold. Marion quirky changes her mind and give him another drink, which Ravinel asks for, that soon puts him to sleep and on queer street.
With the dancing and partying going on outside of the house both Marion and Laura take the knocked-out Dr. Ravinel to the bathroom and deep-six him in the water filled bathtub drowning him . Sending his car to the bottom of the nearby swamp the two take Ravinel's body back home and drop him into the pond on the plantation grounds to make it look like he got himself drunk and fell in and drowned. Everything worked to perfection but there turned out to be just one small problem:The next morning Ravinel's body just disappeared into thin air! Even more strange his car, that was underwater in the swamp, popped up back at the plantation driven there by Ravinel's cousin Vincent, Michael Aubley, who said that Ravinel is in perfect health and staying at a hotel back in New Orleans.
Who was drugged and later drowned by Marion and Laura? What happened to Ravinel's,if it was really him, body at the bottom of the pond? How did the car that Ravinel drove to the bayou and was later submerged there get itself out of the water? And most of all what was Vicent talking about in him seeing and talking to Ravinel hours after he was supposedly killed by the two women?
The second half of the movie is somewhat contrived and nowhere as good as the first half. There's a number of twists in it that are not that surprising but the ending is a bit of a shock. It has a lot to do with Evangaline who we see at the beginning of the film telling the story, in flashback, to the officer in charge at the murder scene Sgt. Joe DuBois,Michael Boatman. Not at first believing a world of what Evangaline told him Sgt. DuBois has a quick change of mind when he looks up at the bedroom widow and sees something or someone thats not, in all logic, supposed to be there!