Excellent work all around especially by the actress who played the wife Gerda (Claire Price) as well, of course, as David Suchet. I did really figure out whodunit but that is beside the point. The ending, which I won't divulge (someone describes it on the Board in answer to someone else's question if you are interested.) I found really sad. Despite Agatha Christie's reputation for writing cardboard characters, I thought these really well-rounded by and large.
The pacing of the story was good and I enjoyed seeing Sarah Miles as Lucy and Edward Hardwicke (Cedric's son I believe in addition to being a well-known Dr. Watson.)) as her husband.