Weak version of the Christie novel...
They took a top Christie story and butchered it. This could have been so much better. The only really good thing about it is the opening with Helen Hayes which is very faithful to the book.
The rest of the story is bogged down by the silly romance between Bixby and Lesley-Anne Down with little development of the other characters. De Havilland's role is so diluted that the ending comes off as weak and unreal.
The worse thing is that they took it out of the original time period (it was '39 in the book) and updated it with a lot of computer nonsense that has nothing to do with adding any merit to the storyline.
Slick and unconvincing, worthwhile only for occasional good moments from Hayes and de Havilland.
"Somewhere along the line, the world has lost all of its standards and all of its taste."