If there's a really clever idea for a classic detective story which all writers in the genre really wish they'd thought of, there's an even chance it was first used by Agatha Christie. In And Then There Were None (originally "Ten Little Niggers" but given a less offensive name, which sounds better anyway, by Christie's American publisher) the idea is this: ten people are trapped in a mansion on a small island, all by themselves, and, after a solemn warning from their anonymous host, are murdered, one by one. Or so it seems. By the end it looks as though they've all been murdered, including the last person to die, who is not (so far as we can tell) the murderer. Of course, this is impossible.

There's not just one clever solution to this puzzle, but two slightly different ones, since when Christie adapted the story for the stage the particular ending used in the book would not have worked. There are three film versions, all of which use the play's ending. This is by common consent the best of the three: brisk, witty, and utterly heartless.

Sabotage is one of Alfred Hitchcock's lesser known features. Perhaps this is because it was one of his pre-Hollywood films or maybe it's just because it doesn't have much of his trademark humour. But what it lacks in humour it certainly makes up for in gripping suspense as we follow the dual life of a terrorist who operates a movie house in London.

Karl Verloc, the cinema owner, is part of a gang of terrorists who are planning a series of attacks in London. Their exact motives are not made clear. Scotland Yard suspects Verloc's involvement in the plot and assigns Detective Sergeant Ted Spencer to investigate, initially undercover. Spencer conducts the investigation posing as a greengrocer's helper, selling fruit and vegetables in a shop next to the cinema. So there you have it, just moments into the movie we know the identity of the saboteur, we know who is the undercover detective, and we know that the police have all but solved the case. And yet in true Hitchcock style there is still so much story to tell. (Sigh, now I have the "Alfred Hitchcock Presents" theme song in my head...)

This film has a lot going for it. The story, characters and acting are all great. And as for the Director, what could be a sweeter film scene than a boy, an old lady, and a puppy on a bus? Well, that depends on if you're Alfred Hitchcock and the film is Sabotage...