Blackmail is of course best known as Alfred Hitchcock's first talking movie. Obviously, being an early attempt at talking pictures, the film's sound would be considered very unpolished by anyone's standards even during that era. Things like car horns, tweeting birds, etc. are overdone to the point of being somewhat of a nuisance at times. And the accent of Czech actress, Anny Ondra, was thought to be too thick for a talking movie, so she mouthed her lines while English actress, Joan Barry read them into a microphone off screen.The film stars Ondra as Alice White, a young and coy woman in her mid twenties who, after flirting with artist/playboy Mr. Crewe (portrayed by Cyril Ritchard in excellent form), finds that her flirtatiousness has placed her in serious jeopardy. A situation arises in which Scotland Yard is called in, and who should show up on the scene but Alice's boyfriend (who she had a slight run-in with the day before) Detective Frank Webber played by John Longden. The blackmail comes in when a vagabond by the name of Tracy, played by Donald Calthrop, who is the only witness with any information on the crime tries to extort money from Frank and Alice. The rest of the film plays out as might be expected, at least in certain ways, yet Hitchcock gives us a somewhat unexpected ending that focuses our attention not on bad guys getting their comeuppance, nor on the prevalence of justice. Rather we're left with a certain pathos that causes us to feel Alice's own remorse accompanied by Frank's mercy toward her, and that mercy comes by way of the old adage that some things in this world are best left unsaid.Also of note in this film is the presence of Sara Allgood who plays Alice's mother. Her time onscreen is short, but we get to see a early sampling of the expressive face, heartfelt emotions, and larger than life image she would be known for in later roles such as that of the family matriarch in How Green Was My Valley (for which she was Oscar nominated).