This was the first Perry Mason film ever made, with Warren William as Mason, who is superb in the part, much better than Raymond Burr, who always annoyed me so much I could not watch the later Perry Mason films. Mason's assistant Della Street is here played by Helen Trenholme, a beautiful and talented choice, but she inexplicably left the film business after making this and one other film in 1934, and that was it. The best performance in the film is by Gordon Westcott, as a distraught client in a state of high anxiety and 'aggravated melancholia'. Unfortunately, he died not long after in a polo accident, which deprived the screen of a real talent. The direction is excellent, with lots of retreating dolly shot 'pullbacks' to add dynamism to the action. Mary Astor does well, but then when did she not? Hats off to Lightning the Dog, who is seen howling splendidly like a wolf in the initial shots of the film. I'd like to have one like that around the house, wouldn't you? Lots of character, not anybody's poodle, not a wimp. The plot of this film is wonderfully complex, a true brain-teaser. This is a Perry Mason film with serious intent, and not a pastiche. It is well worth watching.