My Favorite Brunette (1947)

Baby photographer Ronnie Jackson, on death row in San Quentin, tells reporters how he got there: taking care of his private-eye neighbor's office, Ronnie is asked by the irresistible Baroness Montay to find the missing Baron. There follow confusing but sinister doings in a gloomy mansion and a private sanatorium, with every plot twist a parody of thriller cliches.