So Dark the Night

So Dark the Night – 1946 – United States

While vacationing in the French countryside, a famous Parisian police detective falls in love with an innkeeper’s comely daughter. The young woman presumes the detective is wealthy and ditches her boyfriend to marry him. When her embittered ex-boyfriend appears at the wedding ceremony, the impulsive woman runs away with him instead. Days later, the woman and her boyfriend are found dead. As the detective investigates the apparent murder and suicide, he deduces that a mysterious third party is manipulating the evidence. Other people related to the case start getting killed. The detective reaches the incredible conclusion that he suffers from multiple personality disorder, and he is actually the murderer himself! In a paranoid film noir plot like this, you can bet that the ending is pretty bleak.