Witness for the Prosecution (1957)

 "I am constantly sutprised that women's hats do not provoke more murders..."

This, like Agatha Christie's other play Mousetrap, is known for its twist ending: indeed, there is a voiceover at the end of the film begging us not to spoil it. I'm not necessarily always so fastidious, but on this occasion Christie's secret it safe with me, seven decades later.

I haven't seen the play, but I read a number of Agatha Christie novels in my youth. I recall her ingenious plots, but also her poor characterisation and unfortunate snobbery- good, but no Margery Allingham. That is not in evidence here, and the dialogue (deliciously delivered by the magnificent Charles Laughton and the sublime Marlene Dietrich) is rather witty. Am I misremembering Christie, or has the script had a bit of a polish?

Nevertheless, this is a triumphant film, and certainly the finest courtroom drama I have ever seen: I can see why Christie herself was so happy with Billy Winder's film. The cast (Tyrone Power is a bit of a weak link, but the two stars are magnificent, and there's a fine comic turn from Elsa Lanchester. It's also fascinating to see the workings of a Crown Court in the 1950s, at least via the medium of Hollywood.

The twists and turns are, of course, sublime, and to say that the ending packs a huge punch is a real understatement. This is quite up there with the great twist endings. Yet beyond this we have a triumph of writing, direction and performance. Sublime.